Compounds for deactivating phospholamban function on Ca-ATPase (phopholamban inhibitors)

ABSTRACT

This invention relates to determining the three-dimensional structure of the cytosolic domain of phospholamban (PLB) and its active site from NMR data of sufficiently high resolution for the three-dimensional structure determination. The invention also relates to methods for rational drug design enabling the design of phospholamban inhibitors based on using the three-dimensional structure data provided on computer readable media, as analyzed on a computer system having suitable computer algorithms. The invention also relates to phospholamban inhibiting compounds with certain structural, phsicochemical and spatial characteristics that allow for the interaction of said compounds with specific residues of phospholamban.

This application is continuation-in-part of U.S. Appl. Ser. No. 08/937,117, filed on Sep. 24, 1997, now abandoned entirety of which is incorporated by reference herein.

FIELD OF THE INVENTION

The present invention relates to determining the three-dimensional structure of phospholamban (PLB) using NMR data of sufficiently high resolution for three dimensional structure determination. The invention also relates to methods for rational drug design enabling the design of compounds for deactivating phospholamban based on using the three-dimensional structure data provided on computer readable media, as analyzed on a computer system having suitable computer algorithms. The invention also relates to phospholamban deactivating compounds with structural, physicochemical and spacial characteristics that allow for the interaction of said compounds with specific residues of phospholamban. The interaction prevents the inhibiting effect of phospholamban on Ca-ATPase, making these compounds useful for treating diseases where the Ca-pumping activity of the Ca-ATPase may be diminished, such as congestive heart disease.

BACKGROUND OF THE INVENTION

Phospholamban (PLB) is a low molecular weight protein (52 amino acids), present in cardiac, slow-twitch and smooth muscle, which can be phosphorylated by both cAMP- and Ca²⁺/calmodulin-dependent phosphokinases. The amino acid sequences of phospholamban from different species are shown in FIG. 1. The phosphorylation/ dephosphorylation of phospholamban has been shown to regulate the Ca²⁺-ATPase of the sarco/endoplasmic reticulum in myocytes (SERCA_(—)2). It has been shown that phospholamban, in its non-phosphorylated form, binds to a specific region of the large loop in the cytoplasmic domain of SERCA_(—)2 and inhibits this pump by lowering its affinity for Ca²⁺, while the phosphorylated form does not inhibit SERCA_(—)2.

It has been proposed that a region essential for functional association of phospholamban with Ca²⁺-ATPase lies in the cytoplasmic domain of phospholamban, while the transmembrane region anchors PLB to the sarcoplasmic membrane.

During the last decade, efforts have been made to elucidate, at least partially, the secondary structure of PLB either by means of cross-linking experiments or by reconstitution of SERCA_(—)2 with point-mutated PLB, or, finally, by obtaining direct structural information by circular dichroism, laser light scattering photometry—FTIR spectroscopy and NMR spectroscopy). Molecular modelling has been used to formulate hypotheses on the quaternary structure of the transmembrane region in the PLB pentamer. The structural information obtained has been recently reviewed (Arkin, I. T. et al. (1997) Annu. Rev. Biophys. Biomol. Struct., 26, 157-179).

Since PLB i) is an amphiphatic oligopeptide, ii) contains three cysteins, and iii) is prone to pentamerization also in vitro, it is not straightforward to find good conditions to study its structure and, in particular, an appropriate solvent system which prevents unspecific aggregation. Therefore, until now NMR studies have been carried out either on short PLB fragments or in organic solvents. In no cases has evidence of a tertiary structure for the cytosolic domain of PLB been found.

Inhibition of CaATPases may play a causative role in cardiac disorders where the calcium levels of myocytes are high. As phospholamban inhibits SR CaATPase this inhibition may be harmful in such disorders. A compound capable of relieving the inhibitory effects of phospholamban on cardiac SR Ca²⁺-ATPase, e.g. by interrupting phospholamban-Ca²⁺-ATPase interaction, would be potentially useful in the treatment of such disorders. There have been very few examples on compounds which can prevent the inhibition of CaATPase by phospholamban in the literature. Such compounds include anti-phospholamban antibodies, some large polyanionic oligopeptides and tannins. No small molecules with specific interactions with phospholamban has been reported.

In the present invention it has been found that phospholamban can assume a well characterized conformation in which it can bind a broad series of small compounds with common structural, physicochemical and spacial characteristics that allow an interaction of the said compounds with specific residues of phospholamban in the defined conformation. This interaction deactivates phospholamban and prevents its inhibiting effect on Ca-ATPase. The phospholamban deactivating compounds are potentially useful in the treatment of cardiac disorders, where the activation of the SR CaATPase is beneficial.

SUMMARY OF THE INVENTION

The present invention is based on our complete resolution of the three-dimensional structure of the entire cytosolic domain of phospholamban and the ligand binding site therein.

In one aspect the present invention provides compounds capable of relieving the inhibitory effects of phospholamban on cardiac SR Ca²⁺-ATPase, such compounds thus acting as phospholamban deactivators through direct binding to the phospholamban protein. These componds have common structural, physicochemical and spacial characteristics that allow for the interaction of said compounds with specific residues of the ligand binding site of phospholamban.

In another aspect the present invention provides a method of deactivating phospholamban which comprises administering to a mammal in need thereof a compound of the invention, as well as a pharmaceutical preparation comprising a compound of the invention together with a pharmaceutically acceptable carrier.

In another aspect, the present invention provides methods for rational drug design enabling the design of phospholamban deactivators based on using the three-dimensional structure data of phospholamban cytosolic domain provided on computer readable media, as analyzed on a computer system having suitable computer algorithms.

In still another aspect, the present invention provides the three-dimensional structure of phospholamban cytosolic domain provided on computer readable media.

Other aspects of the present invention will be apparent to one of ordinary skill in the art from the following detailed description and examples relating to the present invention.

BRIEF DESCRIPTION OF THE FIGURES

FIG. 1 shows the amino acid sequences of phospholamban from different species (human, pig, dog, rabbit rat, mouse, chicken).

FIG. 2 is an illustration of the NMR structure of the cyclic peptide cP226.

FIG. 3 is an illustration of the NMR structure of PLB(1-36).

FIG. 4 is an illustration of the model structure of the complex between PLB(1-36) and cyclic peptide cP226.

FIG. 5 is an illustration of the main interactions of cP226 with PLB(1-36) in the model of the binary complex. The distances between the heavy atoms capable for electrostatic binding, H-bonding, or hydrophobic interactions are shown.

FIG. 6 is an illustration showing the PLB amino acid side chains which form the binding site for ligands, divided to four interactions sites denoted as S1-S4.

FIG. 7 is the summary of the observed sequential and medium-range NOE connectivities for PLB(1-36).

FIG. 8 is an illustration of the superposition of compound of Example 1c onto the PLB structure.

FIG. 9 shows the quality of the structure of PLB(1-36) obtained by NOE data. RMSD per residue and the number of restraints per residue is shown.

FIG. 10 is the summary of the observed sequential and medium-range NOE connectivities for cP226.

FIG. 11 is an illustration of the family of 12 structures of cP226 deduced from NMR data.

FIGS. 12A and 12B show the effect of the compound of Example 1c (50 and 100 μM) on the Ca²⁺ uptake rate into the cardiac (A) and fast skeletal muscle (B) SR vesicles.

DETAILED DESCRIPTION OF THE INVENTION

Structure of Phospholamban (1-36)

The present invention is based on our complete resolution of the three-dimensional structure of the entire cytosolic domain of phospholamban (PLB) and the ligand binding site therein. It was possible to determine the structure of the phospholamban cytosolic domain using a method of NMR spectroscopy wherein the NMR data is of sufficiently high resolution for the three-dimensional structure determination. The method comprises providing the 1-36 a.a. fragment of phospholamban, which comprises the cytosolic domain and 6 amino acids of the transmembrane domain, for the NMR analysis in aqueous solution containing 30% trifluoroethanol. The three-dimensional structure can then be determined from the NMR data by distance geometry followed by simulated annealing. The method is described in detail in EXAMPLE 1.

It was found that phospholamban (1-36) fragment assumes a conformation characteristic of a helix-turn-helix motif. The residues of the turn are Ile18, Glu19, Met20, and Pro21, which are adjacent to the two phosphorylation sites Ser16 and Thr17. The proline is in a trans conformation. Both helices have predominantly charged and polar residues on one side, whereas the other is lipophilic. The hydrophilic side of the N-terminal helix faces always the lipophilic side of the C-terminal helix defining a pocket which could be described as an amfiphatic armpit. This may mean that in order to interact with SERCA_(—)2, PLB should assume a prolonged position (i.e. the axes of two α-helices should be nearly parallel), while in the bent conformation those charges would not be exposed to the ATPase but eventually to the surface charges of the phospholipid bilayer. The loose relative positioning of the two helices around the mobile central hinge domain is thus a functional feature of PLB. This flexibility may explain also why, in organic solvent, PLB can assume a prolonged structure.

The structure also reveal that the pocket between the hydrophilic side of the N-terminal helix and the lipophilic side of the C-terminal (defined as an amfiphatic armpit) is an ideal target for small amfiphatic drug molecules designed with the purpose of deactivating PLB by stabilizing its bent conformation. Such molecules would relieve the inhibitory effect of phospholamban on cardiac SR Ca²⁺-ATPase, and therefore act as a PLB deactivator through direct binding to the active site of PLB.

Structure of cP226

In order to find a lead molecule which would interact with PLB a series of peptides were screened. It was found that a cyclic peptide of formula (pI) was able to bind to PLB and activate the calcium intake in liposomes containing both SERCA_(—)2 and PLB while being inactive in liposomes lacking PLB. It was concluded that the cyclic peptide of formula (pI) binds to unphosphorylated PLB and prevents the inhibition exerted by PLB on SERCA_(—)2 thus acting as a PLB deactivator. The cyclic peptide (pI) has the structure:

X is preferably Tyr or Ala.

The cyclic peptide of formula (pI) wherein X is Tyr was named cP226. In order to determine the ligand binding site of PLB, the tertiary structure of the cP226 was resolved by NMR spectroscopy. The method used is described in detail in EXAMPLE 2. The three-dimensional structure of cP226 show bend-coil-bend motif. The lipophilic side chains of Trp-3, Leu-5, Trp-7 and Leu-8 amine clustered on one side of the cyclic peptide, leaving the most of the polar carbonyl and amine groups of the backbone on the other side. The three dimensional coordinates of the cyclic peptide cP226 are provided in Table I annexed to the present application.

Structure of the Complex cP226•PLB(1-36)

On the basis of the resolved tertiary structures of PLB(1-36) and its ligand cP226 it was possible to prepare a model of the complex cP226•PLB(1-36) by molecular modelling. The three-dimensional model describes the interactions between PLB(1-36) and its ligand which are important in binding of ligands to the cytosolic domain of PLB.

The NMR-solved structures of PLB[1-36] and cP226 were used as templates for the building of the complex. cP226 was docked interactively with help of molecular graphics and guided by possible interactions between the two peptides. The structure of cP226 shows that the peptide has two negative side chains (Glu-4 and Glu-6) on one side while the other side is hydrophobic (Trp-7, Leu-8, Pro-9) (FIG. 2). In PLB(1-36) there is a cluster of three positive side chains (Arg-9, Arg-13, Arg-14) opposed by a mainly hydrophobic surface of the C-terminal helix (e.g. Leu-28, Leu-31, Phe-32, Phe-35) (FIG. 3). cP226 was manually docked onto PLB(1-36) so that Glu-4 and Glu-6 come to contact with Arg-9, Arg-13 and Arg-14, while at the same time Trp-7, Leu-8 and Pro-9 are near the hydrophobic surface of PLB C-terminal helix. This gave the starting point for an energy refinement of the complex.

The energy of the obtained complex was minimized by InsightII using the general valence force field (gvff93). Rough minimization was made by the steepest descents method, followed by conjugate gradients and the Newton method.

The structure of the energy minimized complex cP226•PLB(1-36) is shown in FIG. 4. The final total energy of the complex was 113 kcal/mol (non-bond dispersion energy −1574 kcal/mol, coulomb energy −690 kcal/mol).

A schematic sketch of the binding mode of cP226 to PLB is shown in FIG. 5. The binding can be described by four binding sites (S1-S4) which bind Glu4, Glu-6, Trp-7 and Pro-9, respectively (Table II, FIG. 6). Glu-4 has electrostatic/H-bonding interactions with Tyr-6, Arg-9 and Arg-13 (S1), Glu-6 binds to Arg-14 (S2), Trp-7 is buried in a hydrophobic pocket (S3) formed mainly by Met-20, Lys-27 and Leu-28 and Pro-9 binds to a hydrophobic cleft (S4) formed mainly by Phe-32 and Phe-35. Besides, Leu-5 is lined by the hydrophobic part of the side chain of Arg-13 and NH of the indole of Trp-7 can form an H-bond to the carbonyl of Arg-13. The positive N-terminal amino group (NH3+) is near the hydrophobic binding site S4.

TABLE II Binding of cP226 to PLB Site PLB cP226 S1 Tyr-6, Arg-9, Arg-13 Glu-4 S2 Arg-14 Glu-6 S3 Met-20, Lys-27, Leu-28 Trp-7 S4 Phe-32, Phe-35 Pro-9

Thus, the term “binding site S1” is defined as the space surrounded by amino acid residues Tyr-6, Arg-9 and/or Arg-13, particularly —OH group of Tyr-6, guanidinium group of Arg-9 and/or guanidinium group of Arg-13.

The term “binding site S2” is defined as the space surrounded by amino acid residue Arg-14, particularly guanidinium group of Arg-14.

The term “binding site S3” is defined as the space surrounded by amino acid residues Met-20, Lys-27 and/or Leu 28, particularly the side chains thereof.

The term “binding site S4” is defined as the space surrounded by amino acid residues Phe-32 and/or Phe-35, particularly the phenyl groups thereof.

The three dimensional atom coordinates of phospholamban (1-36) in a conformation which allows binding of cyclic peptide cP226 are disclosed in Table III annexed to the present application. The three dimensional atom coordinates of the complex between phospholamban (1-36) and the cyclic peptide cP226 are disclosed in Table IV annexed to the present application. FIG. 8 is an illustration of the superposition of one compound of the invention (compound of Example 1c) onto the PLB structure.

Rational Drug Design

Structure determination methods are also provided by the present invention for rational drug design (RDD) of PLB ligands. Such drug design uses computer modeling programs that calculate different molecules expected to interact with the determined binding sites or other structural or functional domains of PLB. These molecules can then be produced and screened for activity in deactivating PLB according to methods of the present invention.

The present invention reveals the ligand binding site of PLB cytosolic domain heretofor unknown and comprises a distinct three dimensional arrangement of atoms. The atom coordinates of PLB(1-36) in a conformation which allows binding of a PLB deactivator of the invention to the PLB cytosolic domain are disclosed in Table III. This structure for the first time enables the structure-based design of highly active PLB deactivators. The structure of PLB cytosolic domain provided herein permits the screening of known molecules or designing of new molecules which hind to the ligand binding site of PLB cytosolic domain, via the use of computerized evaluation systems. For example, computer modeling systems are available in which the atomic coordinates of PLB cytosolic domain and the ligand binding site thereof as provided in Table III can be used as input. Thus, a computer readable medium may be encoded with data representing the coordinates of Table III in this process.

The present invention provides a method for identifying a PLB deactivator comprising the steps of:

i) providing atom coordinates of the structure of PLB cytosolic domain or portion thereof in a computerized modeling system, ii) identifying compounds which are capable of interacting with said structure, and iii) testing the compounds identified or analogs derived therefrom for the activation of CaATPase in the presence of phospholamban.

In particular, the present invention provides a method for identifying a PLB deactivator comprising the steps of:

i) providing the atom coordinates of the structure of PLB cytosolic domain or portion thereof in a computerized modeling system, ii) identifying compounds which are capable of interacting with at least three of the binding sites S1, S2, S3 and S4 of the PLB cytosolic domain, and iii) testing the compounds identified or analogs derived therefrom for the activation of CaATPase in the presence of phospholamban.

In particular, the present invention provides a method for identifying a PLB deactivator comprising the steps of:

i) providing atom coordinates of the structure of PLB cytosolic domain or portion thereof in a conformation which allows binding of a PLB deactivator to PLB cytosolic domain, in a computerized modeling system, ii) identifying compounds which are capable of said interaction iii) testing the compounds identified or analogs derived therefrom for the activation of CaATPase in the presence of phospholamban.

In the method of the invention candidate molecules may be obtained by carrying out computer-aided molecular design using the three-dimensional structure of the PLB cytosolic domain particularly when complexed with a PLB inhibitor, and in particular the three-dimensional structure at and/or aroud the binding sites S1 to S4, and synthesising the molecules so-designed.

In the method of the invention candidate molecules can be tested for their ability to deactivate phospholamban, for example, using assays which are described in detail in EXAMPLE 3 or modification thereof.

The invention also provides a computer readable medium having stored therein atom coordinates of the structure of the PLB cytosolic domain or portion thereof in a conformation which allows binding of a PLB deactivator to the PLB cytosolic domain.

As used herein. “computer readable media” refers to any medium which can be read and accessed directly by a computer. Such media include, but are not limited to: magnetic storage media, such as floppy discs, hard disc storage medium, and magnetic tape; optical storage mediasuch as optical discs or CD-ROM; electrical storage media such as RAM and ROM; and hybrids of these categories such as magnetic/optical storage media. A skilled artisan can readily appreciate how any of the presently known computer readible media can be used to create a manufacture comprising computer readable medium having stored therein atom coordinates of the structure of the PLB. The choice of the data storage structure will generally be based on the means chosen to access the stored information. Variety of data processor programs and formats can be used to store the atom coordinate data of the present invention on the computer readable medium.

By providing computer readable media having stored therein atom coordinate data of the structure of the PLB, a skilled artisan can routinely access the atom cordinate data of the structure of the PLB cytosolic domain or portion thereof. Computer algorithms are publicly and commercially available which allow a skilled artisan to access this data provided on a computer readable medium and analyze it for structure determination and/or rational drug design. See, e.g. Biotechnology Software Directory, Mary Ann Liebert Publ., New York (1995).

Structural atom coordinates of the PLB(1-36) presented in Table III may be stored in a computer readable form on a computer readable storage medium for display as a three-dimensional shape or for other uses involving computer-assisted manipulation of the structural coordinates they define. For example, data defining the three dimensional structure of a PLB cytosolic domain or portions therof may be stored in a computer readable storage medium, and may be displayed as a graphical three-dimensional representation of the protein structure, typically using a computer capable of reading data from said storage medium and programmed with instructions for creating the representation from such data. The invention thus encompasses a machine, such as a computer, having memory which contains data representing the structural coordinates of the PLB protein of the invention, e.g. coordinates presented in Table III, together additional optonal data and instructions for manipulating such data. Such data can be used for a variety of purposes, such as the rational drug design. The invention encompasses the coordinates of Table III as well as any translation or rotation or the like thereof which maintains the internal coordinates, i.e. which maintains their intrinsic, internal relationship. Those skilled in the art will appreciate that the coordinates may be subjected to other transformations including, e.g. molecular mechanics calculations such as dynamic simulation, minimization, etc.

For example, a first set of computer readable data defining the three-dimensional structure of PLB cytosolic domain or a portion thereof is combined with a second set of computer readable data defining the structure of a candidate molecule using a computer programmed with instructions for evaluating the ability of the candidate molecule to associate PLB cytosolic domain protein and/or the location and/or orientation of such association.

The protein structure encoded by the data may be displayed in a graphical format permitting visual inspection of the structure, as well as visual inspection of the structures association with candidate molecules. Alternatively, more quantitative of computational methods may be used. For example, one method of this invention for evaluating the ability of a candidate molecule to associate with PLB cytosolic domain comprises the steps of i) employing computational means to perform a fitting operation between the candidate molecule and the binding sites of PLB, and ii) analyzing the results of said fitting operation to quantify the association between the candidate molecule and the binding sites of PLB.

One method of this invention provides for selecting from a database of chemical structures a compound capable of binding to PLB cytosolic domain. The method starts with structural coordinates defining the three dimensional structure of PLB cytosolic domain or portion thereof. Binding sites of that three dimensional structure are characterized with respect of the favorability of interactions with one or more functional groups. A database of chemical structures is then searched for candidate compounds containing functional groups disposed for favorable interaction with the PLB based on the prior characterization. Compounds having structures which best fit the points of favorable interaction with three dimensional structure are thus identified.

Computer programs for viewing three dimensional structures or manipulating atom coordinates are available and well known for one skilled in the art.

Phospholamban deactivating compounds

The invention provides phospholamban deactivating compounds being capable of associating with any three of the binding sites S1, S2, S3 and S4 of the PLB cytosolic domain. In particular, the invention provides a phospholamban deactivating compound comprising at least any three of the following:

(a) a first electronegative moiety being capable of associating with the S1 binding site of the PL cytosolic domain when the deactivator is bound thereto said binding site comprising Tyr-6, Arg-9 and/or Arg-13.

(b) a second electronegative moiety being capable of associating with the S2 binding site of the PL cytosolic domain when the deactivator is bound thereto said binding site comprising Arg-14, and

(c) a first hydrophobic moiety being capable of associating with the S3 binding site of the PL cytosolic domain when the deactivator is bound thereto said binding site comprising Met-20, Lys-27 and/or Leu-28.

(d) a second hydrophobic moiety being capable of associating with the S4 binding site of the PL cytosolic domain when the deactivator is bound thereto said binding site comprising Phe-32 and/or Phe-35.

In particular, the invention provides a phospholamban deactivating compound comprising at least any three of the following:

(a) a first electronegative moiety being capable of forming a hydrogen bond with the -OH group of Tyr-6, a salt bridge with the guanidinium group of Arg-9 and/or a salt bridge with the guanidinium group of Arg-13, of the PL cytosolic domain when the deactivator is bound thereto,

(b) a second electronegative moiety being capable of forming a salt bridge with the guanidinium group of Arg-13, of the PL cytosolic domain when the deactivator is bound thereto,

(c) a first hydrophobic moiety being capable of associating with a hydrophobic pocket created by Met-20, Lys-27 and/or Leu-28, of the PL cytosolic domain when the deactivator is bound thereto and.

(d) a second hydrophobic moiety being capable of associating with a hydrophobic pocket created by Phe-32 and/or Phe-35, of the PL cytosolic domain when the deactivator is bound thereto.

In particular, the invention provides a phospholamban deactivating compound comprising:

(a) a first electronegative moiety being capable of forming a hydrogen bond with the -OH group of Tyr-6, a salt bridge with the guanidinium group of Arg-9 and/or a salt bridge with the guanidinium group of Arg-13, of the PL cytosolic domain when the deactivator is bound thereto,

(b) a second electronegative moiety being capable of forming a salt bridge with the guanidinium group of Arg-13, of the PL cytosolic domain when the deactivator is bound thereto and

(c) a first hydrophobic moiety being capable of associating with a hydrophobic pocket created by Met-20, Lys-27 and/or Leu-28, of the PL cytosolic domain when the deactivator is bound thereto and.

Therefore, for a phospholamban deactivator of to the invention, at least three of the first electronegative moiety of (a), the second electronegative moiety of (b), the first hydrophobic moiety of (c) and the second hydrophobic moiety of (d) are capable of forming said hydrogen bond and/or salt bridges of (a), said salt bridge of (b), said associations with the hydrophobic pocket of (c), and said associations with the hydrophobic pocket of (d), respectively, with said groups or hydrophobic pockets of PLB, at the same time.

Phospholamban deactivating compounds of the invention include, but are not limited to, compounds of formula (I) or (II):

in which

R₁ is hydrogen, alkyl, alkenyl, aryl, arylalkyl, hydroxyalkyl, halogenalkyl, alkoxy, COR₁₀, CONR₁₀R₁₁, OR₁₀, S(O)_(m)R₁₀, NR₁₀COR₁₁ or NR₁₀R₁₁, where R₁₀ is hydrogen, alkyl, alkenyl, aryl, arylalkyl, hydroxyalkyl, halogenalkyl, alkoxy or hydroxy and R₁₁ is hydrogen, alkyl, aryl, arylalkyl, alkoxy, aryloxy, hydroxy or acyl, or in case where X is NR₁₁, can R₁ also be carboxylalkyl,

R₆ is hydrogen, alkyl, alkenyl, aryl, arylalkyl,

R₂ and R₇ mean hydrogen, alkyl, aryl, arylalkyl, alkenyl, COR₁₀, CONR₁₀R₁₁, halogen, trifluoromethyl, nitro or cyano, where R₁₀ and R₁₁ are defined as above,

R₃ is hydrogen, alkyl, aryl or arylalkyl,

A means alkyl or substituted alkyl,

m is 0-2 and n is 1-3,

Y means O, NR11 or S, where R11 is the same as above,

X means O, NR11 or S, where R11 is the same as above,

R₄, R₅, R₈ and R₉ mean independently one of the following groups:

 or in case where X is NR₁₁, can R₄, R₅, R₈ and R₉ also independently mean HOOC—, R₁₂OOC—, H₂NCO— or HOHNCO— wherein R₁₂ means alkyl, arylalkyl or aryl, and wherein each aryl residue defined above by itself or as part of another group may be substituted,

 and pharmaceutically acceptable salts and esters thereof.

The compounds of formula (I) or (II) share the structural features which allow them to associate with the ligand binding site of PLB cytosolic domain thereby relieving the the inhibitory effects of PLB on cardiac SR Ca²⁺-ATPase.

Compound s of formula (I) or (II) can be prepared from the 1,3-dihydroxy substituted heteroaromatics by alkylation of the dihydroxy compounds by suitable alkylating agents, for example by chloroacetonitrile or bromoacetic ester according to the following Scheme 1, wherein R₁, R₂, R₃, X and Y are the same as defined above, R′ is a protecting group for the hydroxyl, e.g. methyl, benzyl or tetrahydropyranyl.

The cyano compound (IV) described above is used to prepare the 1,2,4-oxadiazole and 1,2,4-thiadiazole derivatives using the methods described in J. Med. Chem. 1996, 39, 5228-5235.

The syntheses are shown in Scheme 2, wherein R₁, R₂, R₃, X and Y are the same as defined above.

The other heterocyclics as groups R₄, R₅, R₈ and R₉ are prepared as described in Bioorg. Med. Chem. Lett., 1994, 4, 45-50.

The dihydroxyaromatics (III) are made by use of the literature methods. The coumarins (XIV), (XVI) and (XX) are made by the use of the Knoevenagel condensation or von Pechmann reaction as presented in Scheme 3 and 4, where R₁, R₂ and R₃, are the same as defined above, Z is alkyl, aryl, arylalkyl or alkenyl and R′ is a protecting group for the hydroxyls e.g. methyl, benzyl or tetrahydropyranyl.

The quinolinones are prepared by the Knorr reaction as described in Scheme 5, wherein R₁, R₁₁ and R₃ are the same as defined above, X is a halogen.

The cyclic compounds (II) can be prepared correspondingly from compound (XXXI) which can be prepared according to the Scheme 6, wherein R₂ and R₆ are the same as defined above, R′ is a protecting group for the hydroxyls e.g. methyl, benzyl or tetrahydropyranyl.

Cyclic quinolinone compounds (II) can be prepared correspondingly from (XXVI) using Scheme 5.

Salts and esters of the compounds, when applicable, may be prepared by known methods. Physiologically acceptable salts are useful as active medicaments, however, preferred are the salts with alkali or alkaline earth metals. Physiologically acceptable esters are also useful as active medicaments. Examples are the esters with aliphatic or aromatic alcohols.

The term “alkyl” as employed herein by itself or as part of another group includes both straight and branched chain radicals of up to 18 carbon atoms, preferably 1 to 8 carbon atoms, most preferably 1 to 4 carbon atoms. The term “lower alkyl” as employed herein by itself or as part of another group includes both straight and branched chain radicals of 1 to 7, preferably 1 to 4, most preferably 1 or 2 carbon atoms. Specific examples for the alkyl and lower alkyl residues, respectively, are methyl, ethyl, propyl, isopropyl, butyl, tert. butyl, pentyl, hexyl, octyl, decyl and dodecyl including the various branched chain isomers thereof.

The term “acyl” as employed herein by itself or as part of another group refers to an alkylcarbonyl or alkenylcarbonyl group, the alkyl and alkenyl groups being defined above.

The term “aryl” as used herein by itself or as part of another group refers to a monocyclic or bicyclic group containing from 6 to 10 carbon atoms in the ring portion. Specific examples for aryl groups are phenyl, naphtyl and the like. “Aroyl” means in a corresponding way an arylcarbonyl group.

The term “alkoxy” as employed herein by itself or as part of another group includes an alkyl group as defined above linked to an oxygen atom. “Aryloxy” means in a corresponding way an aryl group linked to an oxygen atom.

The term “substituted” as used herein in connection with various residues refers to halogen substituents, such as fluorine, chlorine, bromine, iodine or trifluoromethyl group, amino, alkyl, alkoxy, aryl, alkyl-aryl, halogen-aryl, cycloalkyl, alkylcycloalkyl, hydroxy, alkylamino, alkanoylamino, arylcarbonylamino, nitro, cyano, thiol, or alkylthio substituents.

The “substituted” groups may contain 1 to 3, preferably 1 or 2, most preferably 1 of the above mentioned substituents.

Compound of the invention may be administered to a patient in therapeutically effective amounts which range usually from about 0.1 to 500 mg per day depending on the age, weight, condition of the patient, administration route and the phospholamban deactivator used. The compounds of the invention can be formulated into dosage forms using the principles known in the art. It can be given to a patient as such or in combination with suitable pharmaceutical excipients in the form of tablets, dragees, capsules, suppositories, emulsions, suspensions or solutions. Choosing suitable ingredients for the composition is a routine for those of ordinary skill in the art. It is evident that suitable carriers, solvents, gel forming ingredients, dispersion forming ingredients, antioxidants, colours, sweeteners, wetting compounds and other ingredients normally used in this field of technology may be also used. The compositions containing the active compound can be given enterally or parenterally, the oral route being the preferred way. The contents of the active compound in the composition is from about 0.5 to 100%, preferably from about 0.5 to about 20%, per weight of the total composition.

The following Examples serve purely as an illustration of the various aspects of this invention, and is not intended to be limiting the present invention.

EXAMPLE 1 Structure of the Cytosolic Domain of Phospholamban

Phospholamban (1-36) Synthesis, Purification and Characterization

The cytosolic part of phospholamban peptide having the amino acid sequence MEKVQYLTRSAIRRASTIEMPQQARQKLQNLFINFC was synthesized with an automated peptide synthesizer (Perkin-Elmer, Applied Biosystems 431A) using the fluorenylmethoxycarbonyl strategy. The synthesis was started from the hydrophobic C-terminal end. The side chain protecting groups employed during the synthesis were: Trityl (Trt) for Asn, Gln, and Cys, tert-Butoxy (OtBu) for Glu, tert-Butyl (tBu) for Ser, Thr and Tyr, tert-Butoxycarbonyl (Boc) for Lys and 2,2,5,7,8-Pentamethyl chroman-6-sulphonyl (Pmc) for Arg.

The amount of the preloaded resin was 100 μmol and the quantity of the amino acids at each step of the synthesis was 1 mmol. This is a 10 times excess as compared to the amount of the resin loaded.

The peptide cleavage from the resin support (originally preloaded Wang resin) was performed in methylene chloride containing 5% TFA, 0.2% 13-mercaptoethanol, 0.2% thio anisole and 0.2% dimethylsulfide. Cleavage of the side chain protection of the peptide was carried out in a mixture of ethanedithiol:thioanisole:water:trifluoroaceticacid=250 μl: 500 μl: 500 μl: 10 ml for 1.5 hours at room temperature. After that the peptide was precipitated and washed three times with diethylether, and lyophilized.

The synthesized crude phospholamban (1-36) peptide was prepurified by high performance liquid chromatography (HPLC) technique with an analytical reversed phase (RP) column (C₈, 20 μm, 4.6 mm×30 mm i.d. Perkin-Elmer, Applied Biosystems Brownlee TM column). A linear gradient of acetonitrile (0-100% in 30 min.) in 0.1% TFA was used for elution.

The repurified peptide was futher purified by HPLC RP-chromatography using a C₁₈ Kromasil, 5 μm (1.0×25 cm) column. The peptide was eluted using a stepwise gradient of acetonitrile, 0.075% TFA (3-30%, in 10 min, 30-50% in 120min.) in 0.1% TFA.

The purified phospholamban (1-36) peptide was characterized by SDS-PAGE followed by Coomassie brilliant blue staining. Western blot analysis was done by using the commercial monoclonal anti-PLB antibody (Upstate Biotechnology). The purified RP-chromatography peaks containing the peptide was further analyzed by mass spectrometry (MALDI-TOF) in reflector mode with a BIFLEX™ mass spectrometer using a 337 nm nitrogen laser. The samples were applied in a solution containing 30% acetonitrile/0.1% TFA together with a droplet of sinapinic acid matrix for mass spectrometry analysis. The total amount of purified protein was estimated according to Bradford and also based on RP-chromatography using β-lactoglobulin as a standar reference. The purified peptides were lyophilized and the dry powder was estimated by weight before analysis of the 3-dimensional structure.

Obtaining NMR Spectra of Phospholamban (1-36)

¹H-NMR spectra were acquired at 400.13 MHz and at 599.86 MHz on a Bruker ARX400 and a Varian UNITY 600 NMR spectrometer respectively. 1D and 2D NMR spectra were obtained for a 3 mM solution of the 36-a.a. fragment of PLB in the solvent mixture H₂O:D₂O:d₃-TFE (63:7:30) containing 6 mM d₁₀-DTT to prevent disulphide formation. The pH was adjusted to 3.00+0.02 (uncorrected for deuterium isotope effects) with microliter amounts of NaOD. COSY, TOCSY (30-90 ms) and NOESY (40-400 ms) spectra were recorded at 2, 7, 17 and 27° C., by the States-TPPI method using a spectral width of 8.5 ppm. The 2D data was weighted and Fourier transformed to 2 k×1 k real point matrices. The transmitter presaturated (2.0 s) residual solvent line was reduced by deconvolution. The spectra were referenced to the residual solvent signal (4.75 ppm at 27° C., −10 ppb/° C.). A series often 1D spectra was acquired at different temperatures (ranging from 2 to 47° C.).

Assignment of the NMR Spectra of Phospholamban (1-36)

The spin-system and sequential assignments were derived according to Wüthrich, K. et al. (1986) NMR of Proteins and Nucleic Acids, John Wiley & Sons, Inc., New York, by use of COSY, TOCSY and NOESY spectra acquired at 12, 17 and 27° C. Differences in the temperature dependences of the amido proton chemical shifts were sufficient to unravel resonance overlap. Stereospecific assignments for non-degenerated methylenes were deduced from coupling constants J_(HαHβ) measured from the COSY spectra and from intra residual NOE-cross peak intensities.

Phospholamban (1-36) Structure Generation and Refinement

A series of NOESY spectra was acquired at 17° C. with five different mixing times (50, 80, 120, 160, and 200 ms). The integrated cross peak intensities (I) were used in a NOESY-built-up-analysis. Distance restraints were extracted from the inital slope of a second-order polynomial curve fitted to the volumes of the cross peaks integrated from the NOE-series, with the initial condition I_((τmm=0))=0. Intra methylene and sequential NOEs served for the calibration. The distances were initially classified as short (1.8-2.5 Å), medium (1.8-3.5 Å) or long (3.0-6.0 Å) for the generation of the first set of structures. When a distance could not be calculated from the built-up curve, owing to a partial (>20%) overlap, a poor signal-to-noise ratio or disturbances, it was only required that the distance was <5.0 Å. The upper bounds were extended by 1.0 Å for each pseudo atom. The restraint data were supplemented with distance restraints, which were based on strong, medium and weak NOEs, from the 150 ms NOE-spectrum acquired at 12° C.

Coupling constants (J) were measured by the J-doubling method (McIntyre, L. et al. (1992) J Magn Reson 96, 425-431) from fine structures of COSY cross peaks. Dihedrals φ and χ, which were characterised by intermediate J, were not constrained but small and large J_(NHα) and J_(HαHβ) were related to staggered conformers (±30 degrees) on the basis of Karplus functions and intra residual NOEs (Karplus, M. (1963) J. Am. Chem. Soc., 85, 2870). The H—H distance and dihedral angle restraints were calculated and the data were imported into the software InsightII (Molecular Simulations, Inc.) in order to generate, evaluate and refine the structures. Simulated NOESY spectra were back calculated. The protein coordinate files were analysed by the software PROMOTIF v2.0 (Hutchinson, G. (1995), v2.0 Ed., available by anonymous ftp on 128.40.46.11).

Structures were generated by distance geometry (DGII) followed by simulated annealing (force field AMBER) (Havel, T. et al. (1979) Biopolymers 18, 73). A set of structures was computed. The structures with the least restraint violations were used to back calculate NOE-matrices. If the Hα-chemical shift of consequent residues in the segment characterised by NOEs typical of α-helices departed from the corresponding random coil value more than −0.2 ppm, also the correspondent dihedrals ψ were constrained (±60 degrees). A new set of structures was subsequently calculated. From this new family of structures only those structures with no violations over 0.2 Å were accepted.

Assignment Results

The complete spin-system and sequential assignments were obtained under the experimental conditions described. The assignments are listed in Table V (annexed to the present application) showing H-chemical shifts of PLB(1-36) in 54% H₂O/6% D₂O/30% d₃-TFE, pH 3.05 at 17° C., wherein the staggered conformations are denoted by a line under the chemical shift of C_(β)H in an anti-configuration and by a dashed line in a gauche-configuration (−60 degree) to C_(α)H.

FIG. 7 is a summary of the observed sequential and medium-range NOE connectivities for PLB(1-36) in 54% H₂O/6% D₂O/30% d₃-TFE, at pH 3.05 at 17° C., wherein assignments were made from NOESY spectra acquired at 120, 160 and 200 ms mixing times. Sequential NOEs are represented by shaded blocks. Medium-range NOEs are represented by arrows connecting the appropriate residues. Open circles denote ³J_(NHαCH) coupling constants smaller than 7 Hz. The secondary shift (Δδ) of αCH is defined as the difference between the observed chemical shift and the random coil chemical shift for each residue. Negative (upfield) Δδ values are associated with α-helical secondary structure and positive (downfield) Δδ values with β-structure according to Wishart et al., Biochemistry (1992), 31, 1647-1651.

In total 723 NOEs were assigned. All the 34 possible intra NH—C_(α)H correlations were observed in the finger print region. Most of the corresponding NOEs were fairly strong and comparable to sequential NH_(i+1)—C_(α)H_(i) NOEs (FIG. 7). Many sequential NH_(i)—NH_(i+1) and NH_(i)—NH_(i+2) NOEs were present. Numerous C_(α)H_(i)—NH_(i+3) and some C_(α)H_(i)—NH_(i+4) NOEs were crowded in the finger print region of the NOESY spectra. Furthermore, there were a number of C_(α)H_(i)—C_(β)H_(i+3) cross peaks. NOEs derived from interactions longer than i>i+4 were observed only for protons of Met20.

J-couplings between NH and C_(α)H were small for most residues. Due to overlap of resonances or weak intenstity of COSY cross peaks it was not possible to measure accurate values for all residues but the couplings were below 7-8 Hz with the exception of the residues at the N- and C-terminus and in the center of PLB(1-36).

The central region of the PLB(1-36) does not show a helical character. Namely, the δ_(C)α_(H) values of the residues Glu19, Met20 and Pro21 were not significantly smaller than their random coil values. Glu19 and Met20 were mostly devoid of the NOEs typical of a helical structure, and there were unambiguous strong sequential NOEs between C_(α)H of Glu19 and NH of Met20, and between C_(α)H of Met20 and C_(δ)Hs of Pro21. Furthermore, the NOE between C_(α)H of Ile18 and NH of Glu19 is strong, even when partially buried in the crowded finger print region. All this implies that the central region of PLB(1-36) assumes an extended-like conformation. The extended segment is, nevertheless, short. Thr17 and Gln22 show NOEs and coupling constants characteristic of residues in an α-helix, and there are NOEs from the side chain protons of Glu19 and Met20 to the protons of the adjacent residues in the N- and C-terminal helices. We conclude that the N- and C-terminal α-helices are separated by a turn at Ile18, Glu19, Met20, and Pro21. The proline is in a trans-conformation. A tight turn, which would result the axes of the N- and C-terminal helices being parallel, is not possible. There were no unambiguous NOEs between the N- and C-terminal helices.

Structure of PLB(1-36)

The structure of PLB(1-36) was determined from 599 distances and 50 dihedral restraints excluding those that were defined more accurately by the covalent structure alone. These redundant NOE-derived restraints were consistent with the covalently imposed distance limits, which indicated that the calibration of distances was reasonable. On average there were 16.6 non-trivial NOE-derived restraints per residue. The residues Lys3-Ile18 of the N-terminal helix had on average a few restraints less per residue than the residues Gln22-Cys36 in the C-terminal helix. This is at least partly due to the fact that there were on average more protons with non-degenerated shifts per residue in the C-terminal helix than in the N-terminal helix (Table V). For the residues Ile18-Pro2 1, which confine the turn, there were about as many restraints per residue as there were for the residues in the N-terminal helix.

The structure generation resulted in a family of structures all of which show a helix-turn-helix motif. The root mean square deviation was computed from the family of 20 structures with no distance violations above 0.2 Å and no dihedral violations. FIG. 9 shows the quality of the structure of PLB(1-36) obtained by NOE data wherein RMSD per residue and the number of restraints per residue is shown.

Since no unambiguous long range NOEs were found between the N- and C-terminal helices, the family of structures displayed a dispersion of atomic coordinates in the remote parts of the N- and C-terminal helices. The mutual orientation of the helices was constrained only by the short range distance restraints in the turn. Therefore, RMSD per residue was computed separately i) for the N-terminal helix plus the turn (a.a. 1-21) and ii) for the C-terminal helix plus the turn (18-36). The RMSD represented roughly an inverse correlation with the number of restraints per residue, as expected. In average the atoms in the N-terminal helix were defined to a precision of 1.3 Å (backbone only) and of 2.3 Å (all atoms) and in the C-terminal helix to a precision of 0.8 Å (backbone only) and of 1.9 Å (all atoms). The smallest number of distance violations (below 0.2 Å) were observed for structures in which the segment from Cα of Glu19 to Cα of Pro21 is extended, the side chain of Met20 sticks out approximately parallel to the C-terminal helix and the side chain of Glu19 points almost in the opposite direction. In these structures, the plane of the peptide bond Ile18-Glu19 is approximately orthogonal to the plane of the extended segment.

Owing to the structural mobility of the turn, the family of structures displays a dispersion in the relative position of the N- and C-terminal helices. The dispersion is, nevertheless, limited. When the different structures of the family are superimposed on the Cα of the residues in the C-terminal helixes, the axe of the N-terminal is dispersed in a cone with an opening of approximatively 90 degrees, and with a relative angle of about 80 degrees. Similar mutual orientations for two sequential helices, one of which transmembran and the other anfiphatic, have been found or hypothized for many small membrane bound proteins or peptides (Stopar, D. et al. (1996) Biochemistry, 35 (48), 5467-5473).

In some of the structures, the side chain εNH of Arg9, Arg13 and Arg14, whose chemical shifts are nearly independent of T, make hydrogen bonds with the adjacent side chain oxygen of Ser10, Ser16 and Thr17. For Arg25, with large Δδ_(NH)(T), there were no obvious candidates for hydrogen bond donors. The side chain NH₂ of the glutamines and asparagines could form hydrogen bond net works parallel to the helical axis.

With regards to the phosphorylation of PLB, we find important that the phosphorylation site Ser16 is readily accessible and exposed to the solvent. Thr17, on the N-terminal helix, is facing the C-terminal helix and appears less exposed to the solvent than Ser16. Due to the pitch of the α-helix, Arg13 and Arg14 are also exposed with orientations that lag 60 degrees in phase with respect to Ser16 and Thr17 on the same side of the helix. The presence of positively charged residues in the vicinity of a serine or threonine residue is often seen in a substrate for phosphokinases (e.g. in Troponin I).

We find that one side of the N-terminal helix is predominantly polar or hydrophilic. The same is true for the C-terminal helix, whose polar residues are located on one side while leaving the other side dominated by lipophilic side chains. Owing to the relative orientation of the helices, it can be noted that the hydrophilic side of the N-terminal helix faces always the lipophilic side of the C-terminal helix. This defines a pocket which could be described as an amfiphatic armpit. In this pocket, the relative position of the polar residues on the N-terminal and of the lipophilic residues on the C-terminal can be conveniently described by use of two centroids calculated by averaging the coordinates of selected side chains. The coordinates of the side chains of Arg13, Arg9 and Tyr6 were used to build the centroid relative to the N-terminal and the coordinates of the side chains of Phe32 and Phe35 were used to build up the centroid relative to the C-terminal. The distance between these two centroids was calculated for every structure of the family and was 18.5±4.5 Å. The refined structure of PLB(1-36) is shown in FIG. 3.

EXAMPLE 2 Structure of the Cyclic Peptide cP226

Peptide Synthesis, Cyclization and Purification

The linear peptide having the amino acid sequence CYWELEWLPCA was synthesized with an automated peptide synthesizer (Perkin-Elmer, Applied Biosystems 431A) using the fluorenylmethoxycarbonyl-strategy. The synthesis was started from the carboxy-terminal end. The side chain protecting groups employed during the synthesis were: Trityl (Trt) for Cys, tert-Butoxy (OtBu) for Glu, and tert-Butyl (tBu) for Tyr.

The amount of the preloaded resin was 100 μmol and the quantity of the amino-acids at each step of the synthesis was 1 mmol.

The peptide cleavage from the resin support (originally preloaded Wang resin) as well as cleavage of the side chain pretection groups was carried out in a mixture of ethanedithiol:thioanisole:water:trifluoroaceticacid=250 μl: 500 μl: 500 μl: 10 ml for 1.5 hours at room temperature. After that the peptide was precipitated and washed three times with diethylether, and lyophilized.

The amino-acids and the preloaded resins used for the peptide synthesis were obtained from Novabiochem. Trifluoroacetic-acid (TFA) was produced by Perkin-Elmer, ethanedithiol (EDT) and thioanisole were manufactured by Fluka.

The cyclic peptide cP226 was reconstituted from the linear CYWELEWLPCA peptide by dissolving 0.5 mg/ml the purified peptide into 10 mM (NH₄)₂CO₃ and the oxidation of the SH groups of the two cycteine residues to form intramolecular disulphide bridge was achieved by leaving the solution at room temperature for 1-2 days. The reaction was followed by HPLC chromatography from the peaks of the linear and the cyclic peptide was varied as a fuction of time.

The peptides, both the linear and the cyclic cP226, were purified and separated by reverse phase HPLC-chromatography (C8, Aquqpore Octyl, 30 μm, 10×100 mm, Perkin-Elmer) using 30 min linear gradient from 0.1% TFA to 100% acetonitrile. The obtained peptides were characterized by mass spectrometry.

NMR Spectra of cP226

¹H-NMR spectra were acquired at 400.13 MHz and at 599.86 MHz on a Bruker ARX400 and a Varian UNITY 600 NMR spectrometer respectively. 1D and 2D NMR spectra were obtained for a 1 mM solution of the cyclic peptide in water. The pH was adjusted to 6.50±0.02 (uncorrected for deuterium isotope effects) with microliter amounts of NaOD. COSY, TOCSY (30-90 ms) and NOESY (200-400 ms) spectra were recorded at 5, 10, 15 and 27° C., by the States-TPPI method, using a spectral width of 8.5 ppm. The 2D data was weighted and Fourier transformed to 2 k ∞1 k real point matrices. The transmitter presaturated (2.0 s) residual solvent line was reduced by deconvolution. The spectra were referenced to the residual solvent signal (4.75 ppm at 27° C.,−10 ppb/° C.).

Assignment of the NMR Spectra of cP226

The spin-system and sequential assignments were derived according to Wüthrich as in EXAMPLE 1, by use of COSY, TOCSY and NOESY spectra acquired at 5, 10 and 27° C. Differences in the temperature dependences of the amido proton chemical shifts were sufficient to unravel resonance overlap. Stereospecific assignments for non-degenerated methylenes were deduced from coupling constants J_(HαHβ) measured from the COSY spectra and from intra residual NOE-cross peak intensities.

cP226 Structure Generation And Refinement

A series of NOESY spectra was acquired at 10° C. with different mixing times (200, 300, 400 ms). The integrated cross peak intensities (I) were used in a NOESY-built-up-analysis. Distance restraints were extracted from the inital slope of a second-order polynomial curve fitted to the volumes of the cross peaks integrated from the NOE-series, with the initial condition I_((πm=0))=0. Intra methylene and sequential NOEs served for the calibration. The distances were initially classified as short (1.8-2.5 Å), medium (1.8-3.5 Å) or long (3.0-6.0 Å) for the generation of the first set of structures. When a distance could not be calculated from the built-up curve, owing to a partial (>20%) overlap, a poor signal-to-noise ratio or disturbances, it was only required that the distance was <5.0 Å. The upper bounds were extended by 1.0 Å for each pseudo atom. The restraint data were supplemented with distance restraints, which were based on strong, medium and weak NOEs, from the 300 ms NOE-spectrum acquired at 10° C.

Coupling constants (J) were measured by the J-doubling method from fine structures of COSY cross peaks. Dihedrals φ and χ, which were characterised by intermediate J, were not constrained but small and large J_(NHα) and J_(HαHβ) were related to staggered conformers (±30 degrees) on the basis of Karplus functions and intra residual NOEs. The H—H distance and dihedral angle restraints were calculated. Finally, the data were imported into the software InsightII (Molecular Simulations, Inc.) in order to generate, evaluate and refine the structures. Simulated NOESY spectra were back calculated. The protein coordinate files were analysed by the software PROMOTIF v2.0.

Structures were generated by distance geometry (DGII) followed by simulated annealing (force field AMBER). A set of 30 structures was computed. The structures with the least restraint violations were used to back calculate NOE-matrices. Based on the comparison of the back-calculated and experimental NOE-spectra it became possible to unambiguously identify more NOEs and impose corresponding distance restraints. A new set of 30 structures was subsequently calculated. From this new family, 12 structures with at most one violation larger than 0.3 Å were selected and examined further. The distance restraints corresponding to well-resolved cross peaks were refined by an iterative relaxation matrix method (IRMA) based on a structure without restraint violations (>0.2 Å, >0 deg). The upper bounds were kept within at least 10% of the exact distance given by IRMA to take into account the uncertainty in τ_(c). The refined restraint set was subsequently used to refine the coordinates by simulated annealing.

The resulting final family of 12 structures was visualized by the graphic software MOLMOL (Koradi, R. et al. (1996) J Mol Graphics 14, 51-55).

Assignment Results

The complete spin-system and sequential assignments were obtained under the experimental conditions described. It was necessary to run the NOESY experiments at low temperature (<10° C.) and with relatively long mixing time (>300 ms) to induce enough magnetization transfet and visualize the cross peaks. The assignments are listed in Table VI.

cP226 spectra displayed chemical shift dispersion over 8.5 ppm. C_(α)H shifts ranged from 3.9 to 4.7 ppm and most of the NH shifts were confined between 7.8 and 8.5 ppm, but for Tyr2 and Leu8 the NH resonances were shifted up-field, to 6.9 and 7.3 ppm respectively. There were no signals of methyl groups at very high field (>0 ppm).

FIG. 10 is a summary of the observed sequential and medium-range NOE connectivities for CP226 in 90% H₂O/10% D₂O, pH 6.50 at 10° C. The assignments were made from NOESY spectra acquired at 300 and 400 ms mixing times. Sequential NOEs are represented by shaded blocks. Medium-range NOEs are represented by arrows connecting the appropriate residues. Open circles denote ³J_(NHαCH) coupling constants bigger than 8 Hz. The secondary shift (Δδ) of αCH is defined as the difference between the observed chemical shift and the random coil chemical shift for each residue. Negative (upfield) and positive (downfield) Δδ values are associated to the secondary structure according to Wishart et al., Biochemistry (1992), 31, 1647-1651.

In total 120 NOEs were assigned. Not all the 9 possible intra NH—C_(α)H correlations were observed in the finger print region. Most of the corresponding NOEs were fairly weak. Only four sequential NH_(i)—NH_(i+1) and one NH_(i)—NH_(i+2) NOEs were present. Some NH_(i+n)—C_(β)H_(i) were visible in the NOESY spectra and facilitated the sequential assignment. The secondary shift (Δδ) of αCH, defined as the difference between the observed chemical shift and the random coil chemical shift for each residue, gave evidence of bended structure (FIG. 10). NOEs derived from interactions longer than i>i+4 (across the cycle) were observed for protons of the side chains of Trp3 and Leu8 and for protons of Tyr2 and Cys10.

J-couplings between NH and C_(a)H (measured from the COSY cross peaks) were large for most residues. The couplings for all residues were above 8 Hz, suggesting that the φ angles have predominantly values of 120±30°.The proline was in a trans-conformation.

Structure of cP226

The structure of cP226 was determined from 110 distances and 8 dihedral restraints excluding those that were defined more accurately by the covalent structure alone. These redundant NOE-derived restraints were consistent with the covalently imposed distance limits, which indicated that the calibration of distances was reasonable. On average there were 10 non-trivial NOE-derived restraints per residue. The residues in the central part of the peptide (from Trp3 to Leu8) had more restrain per residue than the average. This is at least partly due to the fact that there were on average more protons with non-degenerated shifts per residue in that zone.

The structure generation resulted in a family of structures all of which show bend-coil-bend motif (MOLMOL). The root mean square deviation was computed from the family of 12 structures with no distance violations above 0.3 Å and no dihedral violations. The small distance restraint violations occurred primarily among the side chain groups, e.g. the tyrosine side chain. This may be a result of excessive mobility in these parts, which could give rise to non-simultaneous NOEs. RMSD per residue was computed and represented roughly an inverse correlation with the number of restraints per residue, as expected. In average the atoms were defined to a precision of 0.96 Å (backbone only) and of 2.02 Å (all atoms) and, if calculed only for the portion from Trp3 to Trp7, to a precision of 0.72 Å (backbone only) and of 1.87 Å (all atoms) (Table VII).

The lipophilic side chains of Trp3, Leu5, Trp7 and Leu8 were clustered on one side of the cyclic peptide, leaving the most of the polar carbonyl and amine groups of the backbone on the other side.

The structure of CP226 shown in this report was docked on the structure of PLB(1-36) described above. The comparison of the two structures confirm the hypothesis that the two glutamate residues on CP226 may partecipate to the binding by coupling with Arg9 and Arg 13 on PLB(1-36), exposing the lipophilic cluster of PC226 to the lipophilic outer part of the C-terminal helix of PLB(1-36).

FIG. 11 shows a family of 12 structures of CP226 deduced from NMR data. The backbones, the heavy atoms of the Trp3 and Trp7 side chains, the heavy atoms of the Glu4 and Glu6 side chains, the carbon β of Glu4 and Glu6 is shown. The distance between the beta carbons of the two glutamate residues (FIG. 11) was highly conservative (8.3±0.9 Å). This information can be useful to design small molecules in which two acetate residues mimic the position of Glu4 and Glu6 on CP226. In the same way, the distance of the lipophilic cluster from the two glutamate residues will also be useful in the drug design process.

EXAMPLE 3 Activity Assays

Experiment 1. Effect on calcium uptake into the SR vesicles prepared from cardiac and fast skeletal muscle

The inhibitory effect of a given compound on phospholamban can be demonstrated by measuring the effect of the compound on calcium uptake into the SR vesicles prepared from cardiac tissue and into SR vesicles prepared from fast skeletal muscle (psoas m.). Both kind of SR vesicles contain Ca²⁺-ATPase but the vesicles from the fast skeletal muscle do not contain phospholamban (Hoh JFY, “Muscle fiber types and function”, Current Opinion in Rheumatology, 4:801-808, 1992). An increase in the calcium uptake into the SR vesicles prepared from cardiac tissue but not into the SR vesicles prepared from fast skeletal muscle indicates that the compound relieves the inhibitory effect of phospholamban on SR Ca²⁺-ATPase and thus acts as a phospholamban inhibitor. Since phospholamban represses both the rates of relaxation and contraction in the mammalian heart through its inhibitory effects on the cardiac SR Ca²⁺-ATPase, a compound relieving these effects is potentially useful in the treatment of heart failure.

Method

Guinea pigs (10-12) were decapited. Their hearts or the psoas muscles were excised, washed in ice-cold 0.9% NaCl and cut into pieces in a buffer containing 20 mM Tris-maleate, 0.3 M sucrose, pH 7.0. Thereafter tissue pieces were homogenized with Polytron and further with Potter (10 strokes). The homogenate was centrifugated at 1000 g for 15 min at 4° C. The supernatant was collected and the pellet was resuspended into 5 ml of the buffer (20 mM Tris-maleate, 0.3 M sucrose, pH 7.0) and recentrifugated at 1000 g for 10 min at 4° C. The obtained supernatant was combined with the earlier collected supernatant and centrifugated once again at 10000 g for 20 min at 4° C. The final supernatant was filtered into a bottle equipped with a magnetic stirrer. KCl was added to the filtered supernatant to achieve the final concentration of 0.6 M (at 4° C.). The obtained solution was centrifugated at 100 000 g for 60 min at 4° C. The pellet was suspended in 5 ml of the buffer containing 20 mM Tris-maleate, 0.3 M sucrose, pH 7.0 and centrifugated at 100 000 g for 60 min at 4° C. The obtained pellet was suspended in 5 ml of buffer containing 20 mM Tris-maleate, 0.3 M sucrose, 0.1 M KCl, pH 7.0 and stored at −80° C. until use. The protein concentration was also measured in order to standardise the separately prepared vesicle preparations.

In the calcium uptake assay, the fluorescent indicator, fluo-3 was used to detect the decrease of the extravesicular Ca²⁺-concentration, when the SR Ca²⁺ATPase was transferring Ca²⁺ from the extravesicular space into the SR-vesicles.

The SR-vesicles obtained above (50 μg protein/ml) were pre-incubated with or without the test compound at 37° C. for 5 min in the assay buffer containing 40 mM imidazole, 95 mM KCl, 5 mM NaN₃, 5 mM MgCl₂, 0.5 mM EGTA, 5 mM potassium oxalate, 2 μM ruthenium red, 5 μM fluo-3, pH 7.0. The free calcium was adjusted to 0.1 μM or to 0.04 μM by CaCl₂. The reaction was initiated by adding ATP (5 mM). The final reaction volume was 1.5 ml. The fluorescence of reaction mixture was measured for 3 min by using the excitation and emission wavelengths of 510 nm and 530 nm, respectively.

Results

FIGS. 12A and 12B show the effect of the compound of Example I c (50 and 100 μM) on the Ca²⁺ uptake rate into the cardiac (A) and fast skeletal muscle (B) SR vesicles. It can be seen that the compound of the invention accelerated the calcium uptake into the cardiac SR vesicles but did not change the calcium uptake into the SR vesicle prepared from the fast skeletal muscle.

Table VIII shows the effects of various compounds of the invention on the Ca²⁺ uptake rate into the cardiac (A) and fast skeletal muscle (B) SR vesicles. The experiments were carried out at 0.1 μM and 0.04 μM free calcium concentrations, respectively.

TABLE VIII Stimulation (%) of the Ca²⁺ uptake into the vesicle preparations obtained from the ventricular myocardium (A) and fast skeletal muscle (B) of the guinea-pig heart. Compound of The stimulation (%) Example No. of Ca²⁺ uptake (100 μM) A B  3c** 51 0  2c 26 −1  7c 5 −17  8g* 18 0 11b 28 nd 12 32 nd 13d*** 23 nd 14c* 18 nd 18e 13 nd 21 11 nd 23**** 20 nd *10 μM, **20 μM, ***50 μM, ****5 μM nd = not determined

Experiment 2. The effects on the left ventricular pressure derivatives

Method

Guinea-pigs of either sex weighing 300-400 g were used in the study. After the guinea-pig was sacrificed by a blow on the skull and decapitated the heart was rapidly excised. The heart was then rinsed in cold oxygenated perfusion buffer. A cannula was inserted into the aorta and secured with a ligature. Retrograde perfusion began as soon as the heart was placed in a thermostatically controlled moist chamber of the Langendorff apparatus. Modified Tyrode solution (37° C.), equilibrated in a thermostatically controlled bulb oxygenator with carbogen (95% O₂ and 5% CO₂) was used as a perfusion buffer. The composition of the Tyrode solution was (in mM): NaCl 135; MgCl₂×6H₂O 1; KCl 5; CaCl₂×2H₂O 2; NaHCO₃ 15; Na₂HPO₄×2H₂O 1; glucose 10; pH 7.3-7.4. The experiments were carried out under constant pressure condition (50 mmHg). After a short prestabilization (10 min) a latex balloon (size 4) was carefully placed into the left ventricle through the left pulmonary vein and the left atrium. The latex balloon was attached to a stainless-steel cannula coupled with a pressure transducer. The latex balloon, the cannula and the chamber of the pressure transducer were filled with ethylene glycol/water (1:1) mixture avoiding any air-bubble. The isovolumetric left ventricular pressure was recorded through the pressure transducer. At the beginning of the experiment, the volume of the balloon was adjusted to obtain a diastolic pressure of approximately 5 mmHg. Before starting the experiment, the heart was allowed to stabilise further for 30-50 min with vehicle (0.1% DMSO) in the perfusion buffer.

After 15 min baseline recording various concentrations of the test compound were added to the perfusion buffer at 15 min intervals. The concentration range of 0.3-30 μM was tested. The vehicle concentration (0.1% DMSO) was kept constant throughout the experiment.

Results

The EC₅₀ values and maximum effects (% change from baseline) of various compounds of the invention on left ventricular systolic pressure are given in Table IX.

TABLE IX The EC₅₀ values and maximum effects (% change from baseline) on left ventricular systolic pressure. Compound of EC₅₀ maximum Example No. (μM) effect (%)  1c 9 +52 at 30 μM  3c 4 +63 at 10 μM  5c >10 +14 at 30 μM  6c 0.5 +25 at 10 μM  7c 2.5 +29 at 10 μM  8g 2 +64 at 10 μM  9d 5 +50 at 30 μM 12 5 +22 at 10 μM 13d 10 +48 at 30 μM 14c 1.5 +25 at 10 μM 15c 3 +37 at 10 μM 16c 10 +57 at 30 μM 18e 10 +35 at 30 μM 19e 6 +39 at 30 μM

EXAMPLE 4

The preparation of PLB deactivators is described below by the following non-limiting examples.

Example 1. Preparation of 3-Benzyl-5,7-bis[(1H-tetrazol-5-yl)-methoxy]-4-methyl-2H-1-benzopyran-2-one

a) 3-Benzyl-5,7-dihydroxy-4-methyl-2H-1-benzopyran-2-one

A solution of phloroglucinol dihydrate (20 g) and ethyl 2-benzylaceto-acetate (27.5 ml) in ethanol (320 ml) was treated with dry HCl at 0° C. for five hours and the solution was kept at that temperature overnight. The yellow solution was concentrated and triturated with water, the solids filtered, washed with water and dried. The resulting hydrate was thrice evaporated to dryness from toluene, triturated with pethroleum ether (bp. 40-60° C.) and filtered. Yield 33.4 g (96%). Melting point 258-260° C.

¹H-NMR (DMSO-d₆, 400 MHz): 2.525 (s, 3H, CH₃), 3.887 (s, 2H, CH₂Ph), 6.171 (d, 1H, J=2,4 Hz), 6.274 (d, 1H, J=2,4 Hz), 7.167-7.279 (m, 5H, Ph), 10.2 (s, 1H, OH), 10.47 (s, 1H, OH).

b) 3-Benzyl-5,7-bis(cyanomethoxy)-4-methyl-2H-1-benzopyran-2-one

Chloracetonitrile (6.86 g), potassium carbonate (23.9 g) and 12.2 g of the product from example 1 a were stirred in 120 ml of DMF at 100° C. under nitrogen for two hours. The reaction mixture was cooled and poured into ice water. The solids were filtered and washed with water. Yield 13.8 g (88%). Melting point 147-154° C.

¹H-NMR (DMSO-d₆, 400 MHz): 2.525 (s, 3H, CH₃), 3.969 (s, 2H, CH₂Ph), 5.307 (s, 2H, OCH₂CN), 5.314 (s, 2H, OCH₂CN), 6.814 (d, 1H, J=2.5 Hz), 6.940 (d, 1H, J=2.5 Hz), 7.18-7.292 (m, 5H, Ph).

c) 3-Benzyl-5,7-bis[(1H-tetrazol-5-yl)methoxy]-4-methyl-2H-1-benzopyran-2-one

The product from example 1b (1 g), sodium azide (0.42 g) and ammonium chloride (0.34 g) were stirred in DMF (5 ml) under nitrogen at 100° C. for 5 hours. The reaction mixture was allowed to cool down and then poured into ice water. The pH of the solution was adjusted to 10-11 and then the solution either extracted once with ethyl acetate or filtered through CELITE. The solution was acidified to pH 2 with hydrochloric acid, kept at 5° C. and filtered. Yield 0.96 g (81%). Melting point 229-233° C.

¹H-NMR (DMSO-d₆, 400 MHz): 2.468 (s, 3H, CH₃), 3.937 (s, 2H, CH₂Ph), 5.596 (s, 2H, OCH₂Tet), 5.602 (s, 2H, OCH₂Tet), 6.832 (d, 1H, J=2.4 Hz), 6.851 (d, 1H, J=2.4 Hz), 7.171-7.283 (m, 5H, Ph).

Example 2. Preparation of 7,8,9,10-Tetrahydro-1,3-bis[(1H-tetrazol-5-yl)methoxy]-7-phenyl-6H-dibenzo[b,d]pyran-6-one

a) 7,8,9,10-Tetrahydro-1,3-dihydroxy-7-phenyl-6H-dibenzo[b,d]pyran-6-one

A solution of phloroglucinol (0.7 g) and 2-ethoxycarbonyl-3-phenylcyclohexanone (1,5 g) in ethanol was treated with dry HCl as described in example 1a. The product was first recrystallized from ethanol-water (1:1) and then triturated with ether. Yield 0.61 g.

¹H-NMR (DMSO-d₆, 400 MHz): 1.38-1.52 (m, 1H), 1.57-1.66 (m, 1H), 1.69-1.78 (m, 1H), 1.86-1.96 (m, 1H), 2.9-3.02 (m, 1H), 3.3-3.4 (m, 1H), 4.050 (b, 1H), 6.157 (d, 1H, J=2.4 Hz), 6.297 (d, 1H, J=2.4 Hz), 7.076-7.265 (m, 5H), 10.153 (s, 1H), 10.456 (s, 1H).

b) 7,8,9,10-Tetrahydro-1,3-bis(cyanomethoxy)-7-phenyl-6H-dibenzo[b,d]pyran-6-one

The product from example 2a (0.5 g) was treated with chloroaceto-nitrile (0.25 g) and potassium carbonate (1.12 g) in DMF (5 ml) as described in example 1b. Yield 0.6 g.

¹H-NMR (DMSO-d₆, 400 MHz): 1.38-1.58 (m, 1H), 1.6-1.7 (m, 1H), 1.7-1.76 (m, 1H), 1.89-1.99 (m, 1H), 2.9-3.03 (m, 1H), 3.2-3.28 (m 1H), 4.111 (b, 1H), 5.314 (s, 2H), 5.349 (s, 2H), 6.840 (d, 1H, J=2.5 Hz), 6.925 (d, 1H, J=2.5 Hz), 7.108-7.274 (m, 5H).

c) 7,8,9,10-Tetrahydro-1,3-bis[(1H-tetrazol-5-yl)methoxy]-7-phenyl-6H-dibenzo[b,d]pyran-6-one

The product from example 2b (0.6 g) was treated with sodium azide (0.2 g) and ammonium chloride (0.17 g) in DMF (5 ml) as in example 1c. The product was recrystallized from a mixture of DMF, ethanol and water (approximately 1:2:3). Yield 0.41 g. Melting point: 153-154° C.

¹H-NMR (DMSO-d₆, 400 MHz): 1.38-1.5 (m, 1H), 1.5-1.6 (m, 1H), 1.69-1.76 (m, 1H), 1.87-1.96 (m, 1H), 2.9-3.05 (m, 1H), 3.2-3.3 (m, 1H), 4.094 (b, 1H), 5.602 (s, 2H), 5.643 (s, 2H), 6.832 (d, 1H, J=2.3 Hz), 6.851 (d, 1H, J=2.3.Hz), 7.089-7.212 (m, 5H).

Example 3. Preparation of 3-Benzyl-5,7-bis[(2,5-dihydro-5-oxo-4H-1,2,4-oxadiazol-3-yl)-methoxy]-4-methyl-2H-1-benzopyran-2-one

a) 3-Benzyl-5,7-bis[(hydroxyamidino)methoxy]-4-methyl-2H-1-benzopyran-2-one

Triethylamine (1.94 ml) was added to a suspension of hydroxylamine hydrochloride (0.97 g) in DMSO (2 ml) and the resulting mixture stirred at room temperature for thirty minutes. The crystals were filtered and washed with THF. The filtrate was concentrated and the product from example 1b (0.5 g) added. This solution was kept at 75° C. overnight. The reaction mixture was treated with ice water, the pH adjusted to 11 and the solids filtered, washed with water, and dried. Yield 0.5 g. Melting point: 155-160° C.

¹H-NMR (DMSO-d₆, 400 MHz): 2.56 (s, 3H, CH₃), 3.938 (s, 2H), 4.466 (s, 2H), 4.486 (s, 2H), 5.565 (s, H, NH₂), 5.709 (s, 2H, NH₂), 6.658 (d, 1H, J=2.4 Hz), 6.692 (d, 1H, J=2.4 Hz), 7.168-7.284 (m, 5H, Ph), 9.346 (s, 1H, OH), 9.362 (s, 1H, OH).

b) 3-Benzyl-5,7-bis[(ethoxycarbonyloxyamidino)methoxy]-4-methyl-2H-1-benzopyran-2-one

Ethyl chloroformiate (0.45 ml) was added to a solution of the product from example 3a (1 g) and pyridin (0.38 ml) in DMF (5 ml) at 0° C. The reaction mixture was kept at that temperature for an additional 30 minutes and then ice water added. The solids were filtered and washed with water. Yield 1.63 g. Melting point 87-92° C.

¹H-NMR (DMSO-d₆, 400 MHz): 1.215-1.256 (m, 6H), 2.553 (s, 3H), 3.947 (s, 2H), 4.140-4.198 (m, 4H), 4.566 (s, 2H), 4.599 (s, 2H), 6.688 (d, 1H, J=2.4 Hz), 6.718 (d, 1H, J=2.4 Hz), 6.792 (b, 2H, NH₂), 6.818 (b, 2H, NH₂), 7.171-7.285 (m, 5H).

c) 3-Benzyl-5,7-bis[(2,5-dihydro-5-oxo-4H-1,2,4-oxadiazol-3-yl)-methoxy]-4-methyl-2H-1-benzopyran-2-one

The product from the previous example (1.5 g) and DBU (0.8 ml) in DMF (5 ml) was stirred at room temperature overnight. The reaction mixture was treated with ice water and acidified. The solids were filtered and washed with water. The resulting solid mass was taken in 0.1 N sodium hydroxide solution, treated with activated carbon and finally acidified. Yield 0.64 g. Melting point: 130-136° C.

¹H-NMR (DMSO-d₆, 400 MHz): 2.524 (s, 3H), 3.954 (s, 2H), 5.187 (s, 2H), 5.215 (s, 2H), 6.748 (d, 1H, J=2.4 Hz), 6.834 (d, 1H, J=2.4 Hz), 7.158-7.289 (m, 5H), 12.8 (b, 2H).

Example 4. Preparation of7,8,9,10-Tetrahydro-bis[(1H-tetrazol-5-yl)methoxy]-1,3-dihydroxy-6H-dibenzo[b,d]pyran-6-one

a) 7,8,9,10-Tetrahydro-1,3-dihydroxy-6H-dibenzo[b,d]pyran-6-one

Phloroglucinol (1 g) and ethyl 2-oxocyclohexane carboxylate (1.32 g) were stirred in 75% sulfuric acid (10 ml) overnight, the mixture poured into ice water and filtered. Yield: 1.55 g.

¹H-NMR (DMSO-d₆, 400 MHz): 1.65 (b, 4H), 2.345 (b, 2H), 3.037 (b, 2H), 6.138 (d, 1H, J=2.4 Hz), 6.245 (d, 1H, J=2.4 Hz), 10.069 (b, 1H, OH), 10.322 (s, 1H, OH).

b) 7,8,9,10-Tetrahydro-bis(cyanomethoxy)-1,3-dihydroxy-6H-dibenzo[b,d]pyran-6-one

The product from the previous example (0.5 g), chloroacetonitrile (0.34 g) and potassium carbonate (1.5 g) in DMF (5 ml) were reacted as in example 1b. Yield: 0.44 g.

¹H-NMR (DMSO-d₆, 400 MHz): 1.68 (b, 4H), 2.41 (b, 2H), 3.00 (b, 2H), 5.297 (s, 2H), 5.309 (s, 2H), 6.797 (d, 1H, J=2.4 Hz), 6.899 (d, 1H, J=2.4 Hz).

c) 7,8,9,10-Tetrahydro-bis[(1H-tetrazol-5-yl)methoxy]-1,3-dihydroxy-6H-dibenzo[b,d]pyran-6-one

The product from the previous example (0.4 g) was treated with sodium azide (0.18 g) and ammonium chloride (0.14 g) in DMF (2.5 ml) as in example 1c. The product was recrystallized from ethanol-DMF (1:1). Yield 0.17 g. Melting point 283-286° C.

¹H-NMR (DMSO-d₆, 400 MHz): 1.626 (b, 4H), 2.393 (b, 2H), 2.971 (b, 2H), 5.583 (s, 2H), 5.599 (s, 2H), 6.811 (s, 2H).

Example 5. Preparation of 5,7-Bis[(1H-tetrazol-5-yl)methoxy]-4-phenyl-2H-1-benzopyran-2-one

a) 5,7-Dihydroxy-4-phenyl-2H-1-benzopyran-2-one

A solution of phloroglucinol (2.00 g) and ethyl benzoylacetate (3.05 g) in ethanol (30 ml) was treated with dry HCl as described in example 1a. The product was recrystallized from ethanol-water (1:1). Yield 3.0 g (75%).

¹H-NMR (DMSO-d₆, 300 MHz): 5.739 (s, 1H, CH═C), 6.155 (d, 1H, J=2.3 Hz), 6.263 (d, 1H, J=2.3 Hz), 7.305-7.381 (m, 5H, Ph), 10.084 (s, 1H, OH), 10.368 (s, 1H, OH).

b) 5,7-bis(cyanomethoxy)-4-phenyl-2H-1-benzopyran-2-one

The product from previous example (1.00 g) was treated with chloroaceto-nitrile (0.62 g) and potassium carbonate (2.72 g) in DMF (5 ml) as described in example 1b. The reaction mixture was poured into ice water and the mixture extracted with ethyl acetate. Ethyl acetate was washed with 1 M NaOH, dried with sodium sulfate and evaporated. The product was recrystallized from isopropanol. Yield 0.41 g (31%).

¹H-NMR (DMSO-d₆, 300 MHz): 4.845 (s, 2H, OCH₂CN), 5.344 (s, 2H, OCH₂CN), 6.086 (s, 1H, CH═C), 6.770 (d, 1H, J=2.4 Hz), 7.040 (d, 1H, J=2.4 Hz), 7.320-7.443 (m, 5H, Ph).

c) 5,7-Bis[(1H-tetrazol-5-yl)methoxy]-4-phenyl-2H-1-benzopyran-2-one

The product from previous example (0.40 g) was treated with sodium azide (0.16 g) and ammonium chloride (0.14 g) in DMF (2 ml) at 100° C. for 2 hours. The product was isolated as described in example 1c. Yield: 0.40 g (79%). Melting point 222-224° C.

¹H-NMR (DMSO-d₆, 400 MHz): 5.148 (s, 2H, OCH₂Tet), 5.649 (s, 2H, OCH₂Tet), 5.968 (s, 1H, CH═C), 6.811 (d, 1H, J=2.3 Hz), 6.962 (d, 1H, J=2.3 Hz), 6.994-7.185 (m, 5H, Ph).

Example 6. Preparation of 7,8,9,10-Tetrahydro-1,3-bis[(1H-tetrazol-5-yl)methoxy]-8-phenyl-6H-dibenzo[b,d]pyran-6-one

a) 7,8,9,10-Tetrahydro-1,3-dihydroxy-8-phenyl-6H-dibenzo[b,d]pyran-6-one

A solution of phloroglucinol (1.56 g) and ethyl 2-oxo-5-phenylcyclo-hexane-carboxylate (2.52 g) in ethanol (25 ml) was treated with dry HCl as described in example 1a. The precipitate was filtered and washed with water and EtOH. Yield 1.0 g (32%).

¹H-NMR (DMSO-d₆, 400 MHz): 1.72-1.82 (m, 1H), 2.01 (b, 1H), 2.317-2.387 (m, 1H), 2,707-2,763 (m, 1H), 2,830 (b, 1H), 3,041 (b, 1H), 3.35 and 3.40 (b, 1H), 6.174 (d, 1H, J=2.3 Hz), 6.277 (d, 1H, J=2.3 Hz), 7.200-7.350 (m, 5H, Ph), 10.131 (s, 1H, OH), 10.401 (s, 1H, OH).

b) 7,8,9,10-Tetrahydro-1,3-bis(cyanomethoxy)-8-phenyl-6H-dibenzo[b,d]pyran-6-one

The product from previous example (1.0 g) was treated with chloro-acetonitrile (0.57 g) and potassium carbonate (1.0 g) in DMF (5 ml) as described in example 1b. DMF was evaporated and residue dissolved in EtOAc. Ethyl acetate was washed with 1 M NaOH, dried with sodium sulfate and evaporated. The product was recrystallized from acetone-isopropanol (1:3). Yield 0.50 g (40%).

¹H-NMR (DMSO-d₆, 300 MHz): 1.75-1.88 (m, 1H), 2.05 (b, 1H), 2.38-2.48 (m, 1H), 2.77-2.85 (m, 1H), 2.90 (b, 1H), 3.07 (b, 1H), 3.22 and 3.28 (b, 1H), 5.316 (s, 2H, OCH₂CN), 5.331 (s, 2H, OCH₂CN), 6.829 (d, 1H, J=2.5 Hz), 6.939 (d, 1H, J=2.5 Hz), 7.210-7.380 (m, 5H, Ph).

c) 7,8,9,10-Tetrahydro-1,3-bis[(1H-tetrazol-5-yl)methoxy]-8-phenyl-6H-dibenzo[b,d]pyran-6-one

The product from previous example (0.30 g) was treated with sodium azide (0.10 g) and ammonium chloride (0.09 g) in DMF (2 ml) at 100° C. for 3.5 hours. The product was isolated in the same manner as in example 1c. Yield 0.30 g (82%). Melting point 235-245° C.

¹H-NMR (DMSO-d₆, 400 MHz): 1.70-1.80 (m, 1H), 1.96 (b, 1H), 2.38-2.446 (m, 1H), 2.836 (m, 2H), 3.052 (b, 1H), 3.252 and 3.301 (b, 1H), 5.604 (s, 2H, OCH₂CN), 5.632 (s, 2H, OCH₂CN), 6.827 (d, 1H, J=2.5 Hz), 6.858 (d, 1H, J=2.5 Hz), 7.209-7.351 (m, 5H, Ph).

Example 7. Preparation of 5,7-Bis[(1H-tetrazol-5-yl)methoxy]-4-methyl-3-(2-phenylethyl)-2H-1benzopyran-2-one

a) 5,7-Dihydroxy-4-methyl-3-(2-phenylethyl)-2H-1-benzopyran-2-one

A solution of phloroglucinol (0.87 g) and ethyl 2-(2-phenylethyl)-acetoacetate (1.62 g) in ethanol (30 ml) was treated with dry HCl as described in example 1a. Yield: 1.77 g (87%). Melting point 248-252° C.

¹H-NMR (DMSO-d₆, 300 MHz): 2.413 (s, 3H, CH₃), 2.652-2.782 (m, 4H, CH₂CH₂), 6.151 (d, 1H, J=2.4 Hz), 6.256 (d, 1H, J=2.4 Hz), 7.183-7.304 (m, 5H, Ph), 10.137 (s, 1H, OH), 10.369 (s, 1H, OH).

b) 5,7-Bis(cyanomethoxy)-4-methyl-3-(2-phenylethyl)-2H-1-benzopyran-2-one

The product from previous example (0.90 g) was treated with chloroacetonitrile (0.48 g) and potassium carbonate (2.1 g) in DMF (5 ml) at 100° C. for 0.5 hours. The product was isolated as described in example 1b. Yield 1.00 g (88%). Melting point 179-183° C.

¹H-NMR (DMSO-d₆, 300 MHz): 2,384 (s, 3H, CH₃), 2.699-2,754 (m, 2H, CH₂CH₂), 2.805-2.841 (m, 2H, CH₂CH₂), 5,302 (s, 4H, OCH₂CN), 6,790 (d, 1H, J=2.5 Hz), 6.909 (d, 1H, J=2.5 Hz), 7.190-7.307 (m, 5H, Ph).

c) 5,7-Bis[(1H-tetrazol-5-yl)methoxy]-4-methyl-3-(2-phenylethyl)-2H-1benzopyran-2-one

The product from previous example (0.40 g) was treated with sodium azide (0.15 g) and ammonium chloride (0.12 g) in DMF (2 ml) at 100° C. for 2.5 hours. The product was isolated as described in example 1c. Yield 0.385 g (78%). Melting point 248-250° C.

¹H-NMR (DMSO-d₆, 400 MHz): 2.368 (s, 3H, CH₃), 2.668-2.707 (m, 2H, CH₂CH₂), 2.783-2.822 (m, 2H, CH₂CH₂), 5.593 (s, 2H, OCH₂Tet), 5.604 (s, 2H, OCH₂Tet), 6.819 (d, 1H, J=2.3 Hz), 6.834 (d, 1H, J=2.3 Hz), 7.161-7.291 (m, 5H, Ph).

Example 8. Preparation of 5,7-bis[(1H-Tetrazol-5-yl)methoxy]-1,3-dibenzyl-4-methyl-2(1H)-quinolinone

a) 2-Benzyl-3-oxobutanoic acid 3,5-dimethoxyanilid

3,5-Dimethoxyaniline (5 g) was added in portions to a preheated (160° C.) ethyl 2-benzyl acetoacetate (15 ml) under nitrogen and kept at that temperature for 60 minutes. The cooled solution was diluted with heptane-ethyl ether and filtered. Yield 5.2 g (49%).

¹-H-NMR (DMSO-d₆, 300 MHz): 2.183 (s, 3H), 3.069 (d, 2H, J=7.2 Hz), 3.923 (t, 1H, J=7.2 Hz), 6.616 (dd. 1H, J=2.3 Hz), 6.765 (d, 2H, J=2.3 Hz), 7.13-7.3 (m, 5H), 10.123 (s, 1H).

b) 3-Benzyl-5,7-dimethoxy-4-methyl-2(1H)-quinolinone

The product from the previous example (1.2 g) was added to a preheated (85° C.) methanesulfonic acid (3.5 ml) and kept at that temperature for 15 minutes. The solution was allowed to cool and then treated with ice water. The product was filtered, washed with sodium bicarbonate and water. Yield 1.08 g (95%).

¹-H-NMR (300 MHz): .486 (s, 3H), 3.785 (s, 3H), 3.808 (s, 3H), 3.985 (s, 2H), 6.315 (d, 1H, J=2.4 Hz), 6.472 (d, 1H, J=2.4 Hz), 7.1-7.3 (m, 5H), 11.52 (s, 1H).

c) 3-Benzyl-5,7-dihydroxy-4-methyl-2(1H)-quinolinone

The product from the previous example (I g) was refluxed under nitrogen in pyridine hydrochloride (5 g) for twenty minutes. The reaction mixture was treated with water and the product filtered. Yield 0.9 g (100%). Melting point: 307-312° C.

¹-H-NMR (300 MHz): .503 (s, 3H), 3.942 (s, 2H), 6.102 (d, 1H, J=2.3 Hz), 6.187 (d, 1H, J=2.3 Hz), 7.1-7.25 (m, 5H), 9.725 (s, 1H), 9.984 (s, 1H), 11.285 (s, 1H).

d) 1,3-Dibenzyl-5,7-dimethoxy-4-methyl-2(1H)-quinolinone

The product from the example 8b (1 g), potassium t-butoxide (0.62 g) and benzyl bromide (0.68 ml) were stirred in DMSO (10 ml) at 60° C. for 4 hours. The reaction mixture was treated with water, extracted with toluene and evaporated. The product was triturated with ethyl ether and filtered. Yield 0.5 g (39%).

¹-H-NMR (400 MHz): 2.537 (s, 3H), 3.708 (s, 3H), 3.826 (s, 3H), 4.124 (s, 2H), 5.56 (b, 2H), 6.413-6.434 (m, 2H), 7.154-7.332 (m, 10H).

e) 1,3-Dibenzyl-5,7-dihydroxy-4-methyl-2(1H)-quinolinone

The product from the previous example (2 g) was treated with pyridine hydrochloride (10 g) as described in example 8c. The product was extracted with ethyl acetate and evaporated. Yield 1.4 g (75%).

¹-H-NMR (400 MHz): 2.570 (s, 3H), 4.076 (s, 2H), 5.450 (b, 2H), 6.135 (d, 1H, J=2.2 Hz), 6.199 (d, 1H, J=2.2 Hz), 7.128-7.333 (m, 10H), 9.83 (b, 1H), 10.166 (s, 1H).

f) 5,7-Bis(cyanomethoxy)-1,3-dibenzyl-4-methyl-2(1H)-quinolinone

The product from the previous example (1.4 g) was treated with chloroacetonitrile (0.76 g) and K₂CO₃ (2.5 g) in DMF (20 ml) as described in example 1b. Yield 1.5 g (89%).

¹-H-NMR (400 MHz): 2.555 (s, 3H), 4.146 (s, 2H), 5.214 (s, 2H), 5.275 (s, 2H), 5.578 (s, 2H), 6.735 (s, 2H), 7.13-7.33 (m, 10H).

g) 5,7-Bis[(1H-tetrazol-5-yl)methoxy]-1,3-dibenzyl-4-methyl-2(1H)-quinolinone

The product from the previous example (1.3 g) was treated with sodium azide (0.41 g) and ammonium chloride (0.34 g) as described in example 1c. Yield: 0.69 g (45%).

¹-H-NMR (400 MHz): 2.471 (s, 3H), 4.113 (s, 2H), 5.477 (s, 2H), 5.55 (b, 2H), 5.574 (s, 2H), 6.670 (d, 1H, J=2.1 Hz), 6.775 (d, 1H, J=2.1 Hz), 7.13-7.32 (m, 10H).

Example 9. Preparation of 5,7-Bis[(1H-tetrazol-5-yl)methoxy]-3-benzyl-1,4-dimethyl-2(1H)-quinolinone.

a) 3-Benzyl-5,7-dimethoxy-1,4-dimethyl-2(1H)-quinolinone

The product from example 8b (0.5 g), t-BuOK (0.2 g) and methyl iodide (0.4 ml) were stirred in DMSO (5 ml) at 35° C. for two days. The reaction mixture was treated with water and extracted with toluene. The product was purified by column chromatography using toluene-ethyl acetate-acetic acid 8:2:1 as the eluent. Yield 0.24 g (46%).

¹-H-NMR (300 MHz): 2.51 (s, 3H), 3.632 (s, 2H), 3.846 (s, 3H), 3.896 (s, 3H), 4.047 (s, 2H), 6.468 (d, 1H, J=2.3 Hz), 6.558 (d, 1H, J=2.3 Hz), 7.1-7.26 (m, 5H).

b) 3-Benzyl-5,7-dihydroxy-1,4-dimethyl-2(1H)-quinolinone

The product from the previous example (0.2 g) was treated with pyridine hydrochloride (2 g) as described in example 8c and the product extracted with ethyl acetate. Yield 0.16 g (89%).

¹-H-NMR (400 MHz): 2.567 (s, 3H), 3.515 (s, 3H), 4.005 (s, 2H), 6.244 (d, 1H, J=2.3 Hz), 6.268 (d, 1H, J=2.3 Hz), 7.08-7.25 (m, 5H), 9.879 (s, 1H), 10.113 (s, 1H).

c) 5,7-Bis(cyanomethoxy)-3-benzyl-1,4-dimethyl-2(1H)-quinolinone

The product from the previous example (0.15 g), chloroacetonitrile 0.08 g) and K₂CO₃ (0.28 g) were reacted in DMF (2 ml) as described in example 1b. Yield 0.16 g (84%).

¹-H-NMR (400 MHz): 2.524 (s, 3H), 3.658 (s, 3H), 4.079 (s, 2H), 5.292 (s, 2H), 5.379 (s, 2H), 6.766 (d, 1H, J=2.3 Hz), 6.855 (d, 1H, J=2.3 Hz), 7.13-7.24 (m 5H).

d) 5,7-Bis[(1H-tetrazol-5-yl)methoxy]-3-benzyl-1,4-dimethyl-2(1H)-quinolinone

The product from the previous example (0.15 g) was treated with NaN₃ (57 mg) and NH₄Cl (47 mg) in DMF (2 ml) as described in example 1c. Yield 0.115 g. Melting point: 250-253° C.

¹-H-NMR (400 MHz): 2.451 (s, 3H), 3.649 (s, 3H), 4.042 (s, 2H), 6.792 (d, 1H, J=2.2 Hz), 6.833 (d, 1H, J=Hz), 7.1-7.25 (m, 5H).

Example 10. Preparation of 3-Benzyl-5,7-bis[(2-methyl-1H-tetrazol-5-yl)methoxy]-4-methyl-2H-1-benzopyran-2-one and the three isomers.

0.07 ml of methyl iodide was added to a solution of 0.2 g of the product from example 1c and 0.31 g of K₂CO₃ in 2 ml of DMF and the mixture stirred at room temperature for 4 hours. The reaction mixture was poured into ice water and filtered. Yield 0.2 g as a mixture of four regioisomers, melting point 71-76° C.

¹H-NMR (DMSO-d₆, 400 MHz): 2.47 (s, CH₃), 2.48 (s, CH₃), 3.93 (s, CH₂Ph), 4.11 (s, NHC₃), 4.12 (s, NHC₃), 4.15 (s, NHC₃), 4.38 (s, NCH₃), 4.40 (s, NCH₃), 5.51 (s, OHC₂), 5.52 (s, OHC₂), 5.62 (s, OHC₂), 5.67 (s, OCH₂), 6.84-6.91 (m, 2H), 7.16-7.28 (m, 5H, Ph).

Example 11. Preparation of 3-Benzyl-5,7-bis[1-(1H-tetrazol-5-yl)ethoxy]4-methyl-2H-1-benzopyran-2one, mixture of stereoisomers

a) 3-Benzyl-5,7bis[(1-cyano)ethoxy)-4-methyl-2 H-1-benzopyran-2-one

The product from example 1a (1 g), 2-chlorpropionitrile (0.7 g) and potassium carbonate (2 g) were heated in DMF (15 ml) under nitrogen at 110° C. for sixty minutes. The mixture was treated with water, filtered and washed with 1 N NaOH and water. Yield 1.2 g.

¹H-NMR (DMSO-d₆, 300 MHz): 1.74-1.78 (t+t, 6H, CH—CH₃), 2.53 (s, 3H), 3.97 (s, 2H), 5.58-5.66 (m, 2H, CH—CH₃), 6.87 (m, 1H), 6.99 (d, 1H), 7.18-7.31 (m, 5H).

b) 3-Benzyl-5,7-bis[1-(1H-tetrazol-5-yl)ethoxy]4-methyl-2 H-1-benzopyran-2-one, mixture of stereoisomers

The product from the previous example (0.5 g), sodium azide (0.18 g) and ammonium chloride (0.15 g) were heated in DMF (7 ml) at 100° C. for 90 minutes. The product was treated with water, extracted with ethyl acetate and evaporated. Yield 0.57 g. Melting point 91-104° C.

¹H-NMR (DMSO-d₆, 300 MHz): 1.69-1.77 (m, 6H, CH—CH₃), 2.54 (s, 3H), 3.94 (s, 2H), 6.10-6.17 ((m, 2H, CH—CH₃), 6.65 (dd, 1H), 6.74 (dd, 1H), 7.13-7.30 (m, 5H).

Example 12. Preparation of 5,7-Bis(carboxymethoxy)-1,3-dibenzyl-4-methyl-2(1H)-quinolinone

The product from example 8f (0.2 g) was refluxed in a solution of concentrated hydrochloric acid (3 ml) and acetic acid (2 ml) for one hour. The product was filtered at 25° C. Yield 0.14 g.

¹H-NMR (300 Mhz, DMSO-d₆): 2.63 (s, CH₃), 4.14 (s, 2H, CH₂Ph), 4.66 (s, 2H, OCH₂COOH), 4.79 (s, 2H, OCH₂COOH), 5.53 (s, 2H, NCH₂Ph), 6.41 (d, 1H, J=2.2 Hz), 6.45 (d, 1H, J=2.2 Hz), 7.13-7.34 (m, 10H, Ph).

Example 13. Preparation of 3-Benzyl-5,7-bis[(1H-tetrazol-5-yl)methoxy]-1-(4-fluorobenzyl)-4-methyl-2(1H)-quinolinone

a) 1-Benzyl-5,7-dimethoxy-3-(4-fluorobenzyl)-4-methyl-2(1H)-quinolinone

The product from example 8b (2 g), potassium-tert-butoxide (0.87 g) and 4-fluorobenzylchloride (1.12 g) were heated in DMSO (20 ml) at 60° C. for three hours as in example 8d. Yield 1.28 g.

¹H-NMR (400 Mhz, DMSO-d₆): 2.53 (s, 3H), 3.73 (s, 3H), 3.83 (s, 3H), 5.55 (s, 2H), 6.43 (s, 2H), 7.12-7.2 (m, 5H), 7.26-7.28 (m, 4H).

b) 3-Benzyl-5,7-dihydroxy-1-(4-fluorobenzyl)-4-methyl-2(1H)-quinolinone

The product from previous example (1.25 g) were heated in pyridine hydrochloride (12.5 g) at about 225° C. for 9 minutes. Yield 1 g.

¹H-NMR (300 Mhz, DMSO-d₆): 2.56 (s, 3H), 4.07 (s, 2H), 5.4 (b, 2H), 6.13 (d, 1H, J=2.1 Hz), 6.20 (d, 1H, J=2.1 Hz), 7.12-7.28 (m, 9H), 9.88 (s, 1H), 10.22 (s, 1H).

c) 3-Benzyl-5,7-Bis(cyanomethoxy)-1-(4-fluorobenzyl)-4-methyl-2(1H)-quinolinone

The product from the previous example (1 g), ClCH₂CN (0.43 g) and K₂CO₃ (1.42 g) were heated in DMF (8 ml) at 120° C. for one hour. Yield 0.94 g.

¹H-NMR (300 Mhz, DMSO-d₆): 2.55 (s, 3H), 4.14 (s, 2H), 5.25 (s, 2H), 5.28 (s, 2H), 5.57 (s, 2H), 6.74 (s, 2H, ArH), 7.1-7.3 (m, 9H).

d) 3-Benzyl-5,7-Bis[(1H-tetrazol-5-yl)methoxy]-1-(4-fluorobenzyl)-4-methyl-2(1H)-quinolinone

The product from the previous example (0.5 g), sodium azide (0.14 g) and ammonium chloride (0.12 g) were heated in DMF (5 ml) at 120° C. for 90 min. The product was triturated with acetonitrile. Yield 0.28 g. Melting point: 126-132° C.

¹H-NMR (300 Mhz, DMSO-d₆): 2.48 (s, 3H), 4.11 (s, 2H), 5.51 (s, 2H), 5.55 (s, 2H), 5.58 (s, 2H), 6.67 (d, 1H, J=2.1 Hz), 6.78 (d, 1H, J=2.1 Hz).

Example 14. Preparation of 5,7-Bis[(1H-tetrazol-5-yl)methoxy]-3-(4-chlorobenzyl)-4-methyl-2H-1-benzopyran-2-one

a) 3-(4-Chlorobenzyl)-5,7-dihydroxy-4-methyl-2H-1-benzopyran-2-one

A solution of phloroglucinol (1.57 g) and ethyl 2-(4-chlorobenzyl)-acetoacetate (3.18 g) in ethanol (25 ml) was treated with dry HCl at 0° C. for 1.5 hours and the solution was kept at that temperature overnight. Solvent was evaporated and the precipitate triturated with water. Yield 3.87 g (98%). Melting point 270-278° C.

¹H-NMR (DMSO-d₆, 300 MHz): 2.52 (s, 3H, CH₃), 3.87 (s, 2H, CH₂), 6.17 (d, 1H, J=2.4 Hz), 6.28 (d, 1H, J=2.4 Hz), 7.18-7.34 (m, 4H, Ph), 10.21 (s, 1H, OH), 10.48 (s, 1H, OH).

b) 5,7-Bis(cyanomethoxy)-3-(4-chlorobenzyl)-4-methyl-2H-1-benzopyran-2-one

The product from the previous example (1.00 g), chloroacetonitrile (0.50 g) and potassium carbonate (2.18 g) were heated in DMF (5 ml) at 100° C. for 30 minutes. The product was isolated as described in example 1b. Yield 0.90 g (72%).

¹H-NMR (DMSO-d₆, 300 MHz): 2.52 (s, 3H, CH₃), 3.95 (s, 2H, CH₂), 5.308 (s, 2H, OCH₂CN), 5.312 (s, 2H, OCH₂CN), 6.81 (d, 1H, J=2.5 Hz), 6.94 (d, 1H, J=2.5 Hz), 7.22-7.33 (m, 4H, Ph).

c) 5,7-Bis[(1H-tetrazol-5-yl)methoxy]-3-(4-chlorobenzyl)-4-methyl-2H-1-benzopyran-2-one

The product from the previous example (0.40 g), sodium azide (0.14 g) and ammonium chloride (0.11 g) were heated in DMF (2 ml) at 100° C. for 2 hours. The product was isolated as in example 1c. Yield 0.40 g (82%).

¹H-NMR (DMSO-d₆, 300 MHz): 2.46 (s, 3H, CH₃), 3.92 (s, 2H, CH₂), 5.602 (s, 2H, OCH₂Tet), 5.609 (s, 2H, OCH₂Tet), 6.83 (d, 1H, J=2.5 Hz), 6.85 (d, 1H, J=2.5 Hz), 7.20-7.33 (m, 4H, Ph).

Example 15. Preparation of 5,7-Bis[(1H-tetrazol-5-yl)methoxy]-3-(4-nitrobenzyl)-4-methyl-2H-1-benzopyran-2-one

a) 5,7-Dihydroxy-4-methyl-3-(4-nitrobenzyl)-2H-1-benzopyran-2-one

A solution of phloroglucinol (0.48 g) and ethyl 2-(4-nitrobenzyl)aceto-acetate (1.00 g) in ethanol (150 ml) was treated with dry HCl at 0° C. for 7.5 hours and the solution was kept at that temperature overnight. Solvent was evaporated and the precipitate triturated with water. Yield 0.63 g (51%). Melting point 280-285° C.

¹H-NMR (DMSO-d₆, 300 MHz): 2.53 (s, 3H, CH₃), 4.03 (s, 2H, CH₂), 6.19 (d, 1H, J=2.4 Hz), 6.29 (d, 1H, J=2.4 Hz), 7.40-7.51 and 8.11-8.17 (m, 4H, Ph), 10.25 (s, 1H, OH), 10.52 (s, 1H, OH).

b) 5,7-Bis(cyanomethoxy)-3-(4-nitrobenzyl)-4-methyl-2H-1-benzopyran-2-one

The product from the previous example (0.57 g), chloroacetonitrile (0.27 g) and potassium carbonate (1.20 g) were heated in DMF (2 ml) at 100° C. for 50 minutes. The product was isolated as described in example 1b. Yield 0.47 g (67%). Melting point 178-185° C.

¹H-NMR (DMSO-d₆, 400 MHz): 2.53 (s, 3H, CH₃), 4.11 (s, 2H, CH₂), 5.319 (s, 2H, OCH₂CN), 5.323 (s, 2H, OCH₂CN), 6.83 (d, 1H, J=2.4 Hz), 6.96 (d, 1H, J=2.4 Hz), 7.48-7.53 and 8.12-8.16 (m, 4H, Ph).

c) 5,7-Bis[(1H-tetrazol-5-yl)methoxy]-3-(4-nitrobenzyl)-4-methyl-2H-1-benzopyran-2-one

The product from the previous example (0.38 g), sodium azide (0.12 g) and ammonium chloride (0.11 g) were heated in DMF (3 ml) at 100° C. for 2 hours. The product was isolated as described in example 1c. Yield 0.25 g (54%). Melting point 240-244° C.

¹H-NMR (DMSO-d₆, 400 MHz): 2.47 (s, 3H, CH₃), 4.08 (s, 2H, CH₂), 5.611 (s, 2H, OCH₂Tet), 5.623 (s, 2H, OCH₂Tet), 6.85 (d, 1H, J=2.4 Hz), 6.87 (d, 1H, J=2.4 Hz), 7.46-7.50 and 8.12-8.16 (m, 4H, Ph).

Example 16. Preparation of 5,7-Bis[(1H-tetrazol-5-yl)methoxy]-3-cyclopentyl-4-methyl-2H-1-benzopyran-2-one

a) 3-Cyclopentyl-5,7-dihydroxy-4-methyl-2H-1-benzopyran-2-one

A solution of phloroglucinol (2.00 g) and ethyl 2-cyclopentylaceto-acetate (3.14 g) in ethanol (40 ml) was treated with dry HCl at 0° C. for 2.5 hours and the solution kept at that temperature overnight. Solvent was evaporated and the precipitate purified with flash chromatography eluting with toluene-EtOAc-AcOH (8: 1:1). Yield 1.22 g (29%).

¹H-NMR (DMSO-d₆, 300 MHz): 1.50-1.88 (m, 8H, —(CH₂)₄—), 2.57 (s, 3H, CH₃), 3.25 (m, 1H, CH), 6.11 (d, 1H, J=2.4 Hz), 6.25 (d, 1H, J=2.4 Hz), 10.25 (b, 2H, OH).

b) 5,7-Bis(cyanomethoxy)-3-cyclopentyl-4-methyl-2H-1-benzopyran-2-one

The product from the previous example (0.50 g), chloroacetonitrile (0.31 g) and potassium carbonate (0.61 g) were heated in DMF (2 ml) at 80° C. for 40 minutes. The product was isolated as described in example 1b. Yield 0.56 g (86%).

¹H-NMR (DMSO-d₆, 300 MHz): 1.55-1.90 (m, 8H, —(CH₂)₄—), 2.56 (s, 3H, CH₃), 3.37 (m, 1H, CH), 5.29 (s, 2H, OCH₂CN), 5.31 (s, 2H, OCH₂CN), 6.75 (d, 1H, J=2.5 Hz), 6.88 (d, 1H, J=2.5 Hz).

c) 5,7-Bis[(1H-tetrazol-5-yl)methoxy]-3-cyclopentyl-4-methyl-2H-1-benzopyran-2-one

The product from the previous example (0.30 g), sodium azide (0.13 g) and ammonium chloride (0.11 g) were heated in DMF (1 ml) at 100° C. for 1.5 hours. The product was isolated as described in example 1c. Yield 0.30 g (80%). Melting point 248-252° C.

¹H-NMR (DMSO-d₆, 400 MHz): 1.53-1.89 (m, 8H, —(CH₂)₄—), 2.51 (s, 3H, CH₃), 3.34 (m, 1H, CH), 5.59 (s, 2H, OCH₂Tet), 5.61 (s, 2H, OCH₂Tet), 6.80 (s, 2H).

Example 17. Preparation of 5,7-Bis[(1H-tetrazol-5-yl)methoxy]-4-methyl-3-(1-naphtylmethyl)-2H-1-benzopyran-2-one

a) 5,7-dihydroxy-4-methyl-3-(1-naphtylmethyl)-2H-1-benzopyran-2-one

A solution of phloroglucinol (0.47 g) and ethyl 2-(1-naphtylmethyl)-acetoacetate (1.00 g) in ethanol (20 ml) was treated with dry HCl at 0° C. for 3 hours and the solution kept at that temperature overnight. Solvent was evaporated and the precipitate triturated with water and recrystallized from isopropanol-water (1:1). Yield 0.96 g (78%). Melting point 275-280° C.

¹H-NMR (DMSO-d₆, 400 MHz): 2.45 (s, 3H, CH₃), 4.32 (s, 2H, CH₂), 6.23 (d, 1H, J=2.5 Hz), 6.32 (d, 1H, J=2.5 Hz), 6.97-8.25 (m, 7H, Naph), 10.26 (s, 1H, 10.53 (s, 1H, OH).

b) 5,7-Bis(cyanomethoxy)-4-methyl-3-(1-naphtylmethyl)-2H-1-benzopyran-2-one

The product from the previous example (0.80 g), chloroacetonitrile (0.36 g) and potassium carbonate (0.66 g) were heated in DMF (4 ml) at 100° C. for 1 hour. The product was isolated as in example 1b. Yield 0.30 g (30%).

¹H-NMR (DMSO-d₆, 300 MHz): 2.45 (s, 3H, CH₃), 4.40 (s, 2H, CH₂), 5.34 (s, 2H, OCH₂CN), 5.36 (s, 2H, OCH₂CN), 6.86 (d, 1H, J=2.5 Hz), 7.010 (d, 1H, J=2.5 Hz), 7.016-8.27 (m, 7H, Naph).

c) 5,7-Bis[(1H-tetrazol-5-yl)methoxy]-4-methyl-3-(1-naphtylmethyl)-2H-1-benzopyran-2-one

The product from the previous example (0.25 g), sodium azide (0.080 g) and ammonium chloride (0.072 g) were heated in DMF (2 ml) at 100° C. for 2.5 hours. The product was isolated as described in example 1c. Yield 0.11 g (36%). Melting point 164-174° C.

¹H-NMR (DMSO-d₆, 300 MHz): 2.40 (s, 3H, CH₃), 4.37 (s, 2H, CH₂), 5.63 (s, 2H, OCH₂Tet), 5.65 (s, 2H, OCH₂Tet), 6.87 (d, 1H, J=2.5 Hz), 6.92 (d, 1H, J=2.5 Hz), 6.98-8.26 (m, 7H, Naph).

Example 18. Preparation of 1-Benzyl-5,7-bis-[(1H-tetrazol-5-yl)-methoxy]-4-methyl-2(1H)-quinolinone

a) 5,7-Dimethoxy-4-methyl-2(1H)-quinolinone

tert-Butyl acetoacetate (1.58 g) was heated to 120° C. and 3,5-dimethoxyaniline (1.53 g) dissolved in xylene (4 ml) was added. The mixture was heated at 120-130° C. for 20 minutes and then cooled to room temperature. Methanesulfonic acid (2 ml) was added and the mixture was stirred at ambient temperature for 10 minutes. Water (40 ml) was added and the precipitate filtered and dried. Yield 1.31 g (60%).

¹H-NMR (DMSO-d₆, 300 MHz): 2.50 (s, 3H, CH₃), 3.79 (s, 3H, OCH₃), 3.83 (s, 3H, OCH₃), 6.03 (s, 1H, CH═C), 6.31 (d, 1H, J=2.3 Hz), 6.45 (d, 1H, J=2.3 Hz), 11.4(b, 1H, NH).

b) 1-Benzyl-5,7-dimethoxy-4-methyl-2(1H)-quinolinone

The product from the previous example (1.20 g) was suspended to DMSO (15 ml) and t-BuOK (0.68 g) and benzylbromide (1.03 g) were added. Reaction mixture was stirred at ambient temperature overnight. Water was added and the product extracted to EtOAc. EtOAc was dried and evaporated to dryness. The product was recrystallized from toluene. Yield 0.80 g (47%).

¹H-NMR (DMSO-d₆, 300 MHz): 2.55 (d, 3H, J=1.1 Hz, CH₃), 3.71 (s, 3H, OCH₃), 3.84 (s, 3H, OCH₃), 5.48 (b, 2H, NCH₂), 6.29 (d, 1H, J=1.1 Hz, CH═C), 6.4 (s, 2H), 7.18-7.33 (m, 5H, Ph).

c) 1-Benzyl-5,7-dihydroxy-4-methyl-2(1H)-quinolinone

The product from the previous example (0.69 g) was dissolved to CH₂Cl₂ (14 ml) and the reaction mixture cooled to −20° C. BBr₃ (2.4 g) in CH₂Cl₂ (1M solution) was added and the mixture was allowed to warm to ambient temperature during the night. The precipitate was filtered, washed with CH₂Cl₂ and dissolved to EtOAc. EtOAc was washed with dilute HCl, dryed and evapotated to dryness. Yield 0.34 g (54 %).

¹H-NMR (DMSO-d₆, 300 MHz): 2.56 (d, 3H, J=1.0 Hz, CH₃), 5.33 (b, 2H, NCH₂), 6.11 (d, 1H, J=2.1 Hz), 6.13 (d, 1H, J=1.0 Hz, CH═C), 6.17 (d, 1H, J=2.1 Hz), 7.12-7.34 (m, 5H, Ph), 9.90 (b, 1H, OH), 10.22 (s, 1H, OH).

d) 1-Benzyl-5,7-bis(cyanomethoxy)-4-methyl-2(1H)-quinolinone

The product from the previous example (0.34 g), chloroacetonitrile (0.13 g) and potassium carbonate (0.34 g) were heated in DMF (2 ml) at 100° C. for 1.5 hours. Water was added and the precipitate filtered and dried. The product was recrystallized from isopropanol. Yield 0.20 g (46%).

¹H-NMR (DMSO-d₆, 400 MHz): 2.57 (s, 3H, CH₃), 5.22 (s, 2H, OCH₂CN), 5.30 (s, 2H, OCH₂CN), 5.50 (b, 2H, NCH₂), 6.42 (s, 1H, CH═C), 6.70 (d, 1H, J=2.1 Hz), 6.73 (d, 1H, J=2.1 Hz), 7.21-7.32 (m, 5H, Ph).

e) 1-Benzyl-5,7-bis-[(1H-tetrazol-5-yl)methoxy]-4-methyl-2(1H)-quinolinone

The product from the previous example (0.20 g), sodium azide (0.072 g) and ammonium chloride (0.060 g) were heated in DMF (2 ml) at 100° C. for 3 hours. The product was isolated as described in example 1c. Yield 0.21 g (85%). Melting point 246-249° C.

¹H-NMR (DMSO-d₆, 400 MHz): 2.50 (s, 3H, CH₃), 5.48 (b, 4H, OCH₂Tet, NCH₂), 5.60 (s, 2H, OCH₂Tet), 6.34 (s, 1H, CH═C), 6.64 (d, 1H, J=1.9 Hz), 6.77 (d, 1H, J=1.9 Hz), 7.18-7.32 (m, 5H, Ph).

Example 19. Preparation of 1-Benzyl-5,7-bis[1H-tetrazol-5-yl)methoxy]-3-(2-fluorobenzyl)-4-methyl-2(1H)-quinolinone

a) 5,7-Dimethoxy-3-(2-fluorobenzyl)-4-methyl-2(1H)-quinolinone

Ethyl 2-(2-fluorobenzyl)acetoacetate (2.5 g) in xylene (1 ml) was heated to 150° C. and 3,5-dimethoxyaniline (1.46 g) in xylene (4 ml) was added in small portions during 30 minutes. The reaction mixture was heated at 160° C. for 3 hours and then cooled to room temperature. Methanesulfonic acid (1.7 ml) was added and the mixture was stirred at ambient temperature for 30 minutes. Water was added and the precipitate filtered and dried. The product was triturated with warm ethanol. Yield 0.64 g (21%).

¹H-NMR (DMSO-d₆, 300 MHz): 2.45 (s, 3H), 3.79 (s, 3H), 3.82 (s, 3H), 3.97 (s, 2H), 6.33 (d, 1H, J=2.4 Hz), 6.48 (d, 1H, J=2.4 Hz), 6.90-7.25 (m, 4H), 11.61 (s, 1H).

b) 1-Benzyl-5,7-dimethoxy-3-(2-fluorobenzyl)-4-methyl-2(1H)-quinolinone

The product from the previous example (0.62 g) was treated with t-BuOK (0.23 g) and benzylbromide (0.36 g) in DMSO (12 ml) at 60° C. for 2.5 hours. The product was isolated as described in example 18b. Yield 0.39 g (49%).

¹H-NMR (DMSO-d₆, 400 MHz): 2.51 (s, 3H), 3.72 (s, 3H), 3.84 (s, 3H), 4.11 (s, 2H), 5.55 (b, 2H), 6.433 (d, 1H, J=2.1 Hz), 6.443 (d, 1H, J=2.1 Hz), 6.97-7.33 (m, 9H).

c) 1-Benzyl-5,7-dihydroxy-3-(2-fluorobenzyl)-4-methyl-2(1H)-quinolinone

The product from the previous example (0.34 g) was treated with BBr₃ (8.48 g) in CH₂Cl₂ (7 ml) as described in example 18c. Yield 0.30 g (82%).

¹H-NMR (DMSO-d₆, 400 MHz): 2.55 (s, 3H), 4.06 (s, 2H), 5.40 (b, 2H), 6.13 (d, 1H, J=2.1 Hz), 6.22 (d, 1H, J=2.1 Hz), 6.97-7.33 (m, 9H), 10.3 (b, 2H).

d) 1-Benzyl-5,7-bis(cyanomethoxy)-3-(2-fluorobenzyl)-4-methyl-2(1H)-quinolinone

The product from the previous example (0.21 g), chloroacetonitrile (0.086 g) and potassium carbonate (0.37 g) were heated in DMF (2 ml) at 100° C. for 2 hours. The product was isolated as described in example 1b. Yield 0.18 g (71%).

¹H-NMR (DMSO-d₆, 400 MHz): 2.53 (s, 3H), 4.13 (s, 2H), 5.23 (s, 2H), 5.29 (s, 2H), 5.57 (b, 2H), 6.746 (d, 1H, J=2.3 Hz), 6.756 (d, 1H, J=2.3 Hz), 7.00-7.32 (m, 9H).

e) 1-Benzyl-5,7-bis[1H-tetrazol-5-yl)methoxy]-3-(2-fluorobenzyl)-4-methyl-2(1H)-quinolinone

The product from the previous example (0.17 g), sodium azide (0.051 g) and ammonium chloride (0.042 g) were heated in DMF at 100° C. for 3 hours. The product was isolated as described in example 1c. Yield 0.17 g (85%). Melting point 135-140° C.

¹H-NMR (DMSO-d₆, 400 MHz): 2.46 (s, 3H), 4.10 (s, 2H), 5.48 (s, 2H), 5.51 (b, 2H), 5.59 (s, 2H), 6.68 (d, 1H, J=2.2 Hz), 6.79 (d, 1H, J=2.2 Hz), 6.99-732 (m, 9H).

Example 20. Preparation of 1-Benzyl-5,7-bis[1H-tetrazol-5-yl)-methoxy]-4-methyl-3-(2-phenylethyl)-2(1H)-quinolinone

a) 5,7-Dimethoxy-4-methyl-3-(2-phenylethyl)-2(1H)-quinolinone

Ethyl 2-(2-phenylethyl)acetoacetate (2.70 g) in xylene (5 ml) was treated with 3,5-dimethoxyaniline (1.60 g) at 150° C. as described in example 19a. Methanesulfonic acid (4.0 ml) was added at room temperature and the mixture heated at 80° C. for 1 hour. The product was isolated as described in example 19a. Yield 1.38 g (41%).

¹H-NMR (DMSO-d₆, 400 MHz): 2.45 (s, 3H), 2.64-2.68 (m, 2H), 2.82-2.86 (m, 2H), 3.78 (s, 3H), 3.81 (s, 3H), 6.30 (d, 1H, J=2.3 Hz), 6.45 (d, 1H, J=2.3 Hz), 7.18-7.30 (m, 5H), 11.45 (s, 1H).

b) 1-Benzyl-5,7-dimethoxy-4-methyl-3-(2-phenylethyl)-2(1H)-quinolinone

The product from the previous example (0.61 g), t-BuOK (0.24 g) and benzylbromide (0.36 g) were heated in DMSO (12 ml) at 60° C. for 2 hours. The product was isolated as described in example 18b. Yield 0.31 g (40%).

¹H-NMR (DMSO-d₆, 400 MHz): 2.51 (s, 3H), 2.73-2.77 (m, 2H), 2.96-3.00 (m, 2H), 3.70 (s, 3H), 3.83 (s, 3H), 5.55 (b, 2H), 6.40 (s, 2H), 7.17-7.33 (m, 10H).

c) 1-Benzyl-5,7-dihydroxy-4-methyl-3-(2-phenylethyl)-2(1H)-quinolinone

The product from the previous example (0.31 g) was treated with BBr₃ (0.75 g) in CH₂Cl₂ (5 ml) as in example 18c. Yield 0.26 g (89%).

¹H-NMR (DMSO-d₆, 300 MHz): 2.56 (s, 3H), 2.69-2.75 (m, 2H), 2.90-2.95 (m, 2H), 5.39 (b, 2H), 6.08 (d, 1H, J=2.0 Hz), 6.19 (d, 1H, J=2.0 Hz), 7.11-7.33 (m, 10H), 10.2 (b, 2H).

d) 1-Benzyl-5,7-bis(cyanomethoxy)-4-methyl-3-(2-phenylethyl)-2(1H)-quinolinone

The product from the previous example (0.22 g), chloroacetonitrile (0.091 g) and potassium carbonate (0.39 g) were heated at 100° C. for 2 hours. The product was isolated as in example 1b. Yield 0.20 g (76%).

1H-NMR (DMSO-d₆, 400 MHz): 2.50 (s, 3H), 2.73-2.77 (m, 2H), 2.98-3.02 (m, 2H), 5.21 (s, 2H), 5.29 (s, 2H), 5.56 (b, 211), 6.70 (d, 1H, J=2.1 Hz), 6.72 (d, 1H, J=2.1 Hz), 7.18-7.33 (m, 10H).

e) 1-Benzyl-5,7-bis[1H-tetrazol-5-yl)methoxy]-4-methyl-3-(2-phenylethyl)-2(1H)-quinolinone

The product from the previous example (0.19 g), sodium azide (0.057 g) and ammonium chloride (0.047 g) were heated in DMF at 100° C. for 3 hours. The product was isolated as described in example 1c. Yield 0.18 g (78%). Melting point 215-218° C.

¹H-NMR (DMSO-d₆, 400 MHz): 2.46 (s, 3H), 2.70-2.74 (m, 2H), 2.95-2.99 (m, 2H), 5.47 (s, 2H), 5.54 (b, 2H), 5.57 (s, 2H), 6.64 (d, 1H, J=2.0 Hz), 6.77 (d, 1H, J=2.0 Hz), 7.16-7.33 (m, 10H).

Example 21. Preparation of 5,7-Bis(aminocarbonylmethoxy)-1,3-dibenzyl-4-methyl-2(1H)-quinolinone.

The mixture of 5,7-dihydroxy-1,3-dibenzyl-4-methyl-2(1H)-quinolinone (0.5 g), potassium carbonate (0.9 g) and 2-chloroacetamide (0.25 g) in DMF (6.5 ml) were reacted at 100° C. for two hours. The reaction mixture was treated with ice water and filtered. The product was triturated with hot ethanol. Yield: 0.32 g. Melting point 252-253° C.

¹H-NMR (400 MHz, DMSO-d₆): 2.63 (s, 3H, CH₃), 4.13 (s, 2H, PhCH₂), 4.37 (s, 2H, OCH₂), 4.55 (s, 2H, OCH₂), 5.54 (s, 2H, NCH₂Ph), 6.40 (d, 1H, J=2 Hz, ArH), 6.53 (d, 1H, J=2 Hz, ArH), 7.13-7.33 (m, 10H, Ph), 7.44 (d, 2H, J=65 Hz, CONH₂), 7.47 (d, 2H, J=68 Hz, CONH₂).

Example 22. Preparation of 5,7-Bis(ethoxycarbonylmethoxy)-1,3-dibenzyl-4-methyl-2(1H)-quinolinone.

The mixture of 5,7-dihydroxy-1,3-dibenzyl-4-methyl-2(1H)-quinolinone (1 g), ethyl 2-bromoacetate (0.63 ml) and potassium carbonate (1.49 g) in DMF (5 ml) was heated under nitrogen at 110° C. for three hours, poured into ice water and filtered. The resulting solid material was triturated with ether and filtered again. Yield: 1.03 g, melting point 113-116° C.

¹H-NMR (400 MHz, DMSO-d₆): 1.15 (t, 3H, CH₃CH₂, J=7.1 Hz), 1.20 (t, 3H, CH₃CH₂, J=7.1 Hz), 2.63 (s, 3H, CH₃), 4.03 (q, 2H, CH₂CH₃, J=7.1 Hz), 4.13 (s, 2H, CH₂Ph), 4.17 (q, 2H, CH₂CH₃, J=7.1 Hz), 4.78 (s, 2H, OCH₂), 4.90 (s, 2H, OCH₂), 6.41 (d, 1H, J=2.2 Hz), 6.44 (d, 1H, J=2.2 Hz), 7.13-7.33 (m, 10H, Ph).

Example 23. Preparation of 5,7-Bis(hydroxyaminocarbonylmethoxy)-1,3-dibenzyl-4-methyl-2(1H)-quinolinone

The product from the previous example (0.3 g), hydroxylamine hydrochloride (0.32 g) and 5 N NaOH (1.05 ml) were reacted in ethanol (8 ml) at 50° C. for six hours. The reaction mixture was treated with water and made basic (pH 10) and filtered. The filtrate was acidified to pH 2 and filtered. Yield: 0.2 g, melting point 121-127° C.

¹H-NMR (400 MHz, DMSO-d₆): the tautomeric forms of hydroxamic acid are seen in OCH₂-signals: 2.63 (s, 3H, CH₃), 4.13 (S, 2H, CH₂Ph), 4.41 (s, 2H, OCH₂), 4.54 (s, 2H, OCH₂), 4.64 (s, 2H, HON═C(OH)CH₂O), 4.65 (s, 2H, HON═C(OH)CH₂O), 4.77 (s, 2H, HON═C(OH)CH₂O), 4.78 ((s, 2H, HON═C(OH)CH₂O), 5.54 (s, 2H, NCH₂Ph), 6.38-6.54 (m, 2H, ArH), 7.14-7.34 (m, 10H, Ph), 9.05 (b, 2H, NOH), 10.84 (s, 1H, HONHCO), 10.88 (s, 1H, HONHCO).

EXAMPLE 5 Design of PLB Inhibitors

The three dimensional structure determined for phospholamban can be used as a target for selecting compounds that bind to the protein. In order to have good affinity for phospholamban, the ligand should have steric and electrostatic complementarity with the target. Especially, good electrostatic and/or hydrogen bonding interactions should be formed with the sites S1 and S2, and good hydrophobic interactions should be formed with the sites S3 and S4. Any of the various computer programs and databases available for such purpose can be used to design compounds that fullfill these requirements. The structure-based approaches include de Novo design, computer-based selection of ligands that are complementary with the target and computer-aided optimization of lead molecules. The detection of the PLB binding compounds can proceed by using the following steps:

1. The target region of the protein is selected. The binding model of the effective phospholamban deactivator peptide, cP226, can be used to define an area on the phospholamban surface which can function as a target for phospholamban deactivators. Especially, this determines the side chains of phospholamban which can interact with the compounds to be designed.

2. Small molecules which are complementary to the binding site can be docked to the target by using available software, such as e.g. Ludi, DOCK or LeapFrog. Computer databases of three-dimensional structures of small molecules or molecular fragments can be used in the docking. Such an approach gives molecules or fragments that have good interactions with the various parts of the target area.

3. Different small molecules or fragments that bind to the target area can be linked together or one can incorporate new side chains and/or functional groups to them, so that one gets a single, larger molecule. The resulting new compound is likely to have better affinity to the target than the smaller molecules.

4. One can also select a proper scaffold and dock that by using an interactive molecular graphics system near the binding site of the protein. One can then add new fragments and functional groups to the scaffold, so that the new groups form good interactions with the target surface.

5. The cyclic peptide cP226 is an example of a compound which binds to the ligand binding site of phospholamban. The structure of cP226 can be used as a model for designing new compounds with affinity to phospholamban. Any of the well defined methods for designing peptidomimetics or, more generally, peptide mimics can be used to design such compounds.

A limited number of compounds can be selected through the process outlined above. Anyone skilled with the art would be able to identify such compounds by using the three dimensional structure of phospholamban stored in a computer system. The compounds can be then synthetized and tested for their ability to deactivate phosholamban in an assay similar to that outlined in example 3.

TABLE I Orthogonal three dimensional coordinates in Angströms for the cyclic peptide cP226 Residue Atom X Y Z 1 CYS N −4.500 −5.816 1.065 1 CYS CA −3.913 −5.081 2.195 1 CYS HN1 −4.805 −6.727 1.378 1 CYS HN2 −5.291 −5.300 0.706 1 CYS HN3 −3.811 −5.926 0.337 1 CYS HA −4.673 −5.015 2.974 1 CYS C −3.521 −3.665 1.797 1 CYS O −4.275 −2.984 1.106 1 CYS CB −2.716 −5.833 2.773 1 CYS SG −1.186 −5.807 1.793 1 CYS HB1 −2.485 −5.381 3.737 1 CYS HB2 −3.005 −6.870 2.943 1 CYS LG1 −0.868 −6.293 2.143 1 CYS LG2 −1.298 −5.206 1.500 2 TYR N −2.334 −3.230 2.226 2 TYR CA −1.822 −1.920 1.877 2 TYR HN −1.741 −3.845 2.764 2 TYR HA −2.467 −1.466 1.124 2 TYR C −0.427 −2.065 1.301 2 TYR O −0.005 −3.170 0.967 2 TYR CB −1.782 −1.016 3.105 2 TYR HB1 −0.796 −0.552 3.147 2 TYR HB2 −2.524 −0.231 2.974 2 TYR CG −2.052 −1.724 4.413 2 TYR CD1 −3.368 −1.863 4.872 2 TYR HD1 −4.192 −1.509 4.270 2 TYR CD2 −0.987 −2.180 5.200 2 TYR HD2 0.031 −2.071 4.855 2 TYR CE1 −3.619 −2.453 6.116 2 TYR HE1 −4.634 −2.555 6.471 2 TYR CE2 −1.238 −2.769 6.445 2 TYR HE2 −0.415 −3.115 7.053 2 TYR CZ −2.553 −2.901 6.905 2 TYR OH −2.798 −3.464 8.124 2 TYR HH −1.998 −3.726 8.585 3 TRP N 0.295 −0.949 1.195 3 TRP CA 1.639 −0.990 0.666 3 TRP HN −0.084 −0.061 1.491 3 TRP HA 2.012 −2.004 0.800 3 TRP C 2.542 −0.026 1.422 3 TRP O 2.112 0.623 2.372 3 TRP CB 1.614 −0.654 −0.821 3 TRP HB1 0.826 −1.238 −1.296 3 TRP HB2 1.378 0.404 −0.929 3 TRP CG 2.892 −0.918 −1.546 3 TRP CD1 3.831 0.008 −1.830 3 TRP CD2 3.402 −2.178 −2.077 3 TRP NE1 4.877 −0.580 −2.512 3 TRP CE2 4.664 −1.934 −2.681 3 TRP HD1 3.772 1.053 −1.559 3 TRP HE1 5.708 −0.104 −2.833 3 TRP CE3 2.933 −3.504 −2.103 3 TRP HE3 1.978 −3.737 −1.655 3 TRP CZ2 5.421 −2.947 −3.276 3 TRP HZ2 6.378 −2.724 −3.723 3 TRP CZ3 3.684 −4.528 −2.696 3 TRP HZ3 3.302 −5.538 −2.700 3 TRP CH2 4.927 −4.255 −3.280 3 TRP HH2 5.501 −5.051 −3.731 4 GLU N 3.799 0.056 0.982 4 GLU CA 4.812 0.899 1.576 4 GLU HN 4.087 −0.499 0.192 4 GLU HA 5.405 0.313 2.216 4 GLU C 4.236 2.017 2.406 4 GLU O 4.787 2.431 3.423 4 GLU CB 5.698 1.448 0.481 4 GLU CG 6.679 0.389 −0.014 4 GLU CD 7.595 0.956 −1.091 4 GLU OE1 7.249 0.790 −2.281 4 GLU OE2 8.627 1.545 −0.704 4 GLU HB1 5.027 1.763 −0.302 4 GLU HB2 6.242 2.305 0.856 4 GLU HG1 7.290 0.056 0.824 4 GLU HG2 6.128 −0.462 −0.411 5 LEU N 3.135 2.522 1.889 5 LEU CA 2.622 3.613 2.150 5 LEU HN 2.818 2.140 1.031 5 LEU HA 3.362 4.435 2.574 5 LEU C 1.437 3.723 3.079 5 LEU O 1.552 3.459 4.275 5 LEU CB 2.300 4.379 0.776 5 LEU HB1 1.233 4.331 0.644 5 LEU HB2 2.784 3.725 0.059 5 LEU CG 2.893 5.759 0.516 5 LEU HG 3.808 5.818 1.092 5 LEU CD1 3.275 5.906 −0.959 5 LEU HD11 4.091 5.223 −1.199 5 LEU HD12 2.426 5.670 −1.594 5 LEU HD13 3.598 6.928 −1.157 5 LEU CD2 1.924 6.871 0.916 5 LEU HD21 1.572 6.707 1.933 5 LEU HD22 2.430 7.834 0.854 5 LEU HD23 1.076 6.877 0.232 6 GLU N 0.310 4.034 2.475 6 GLU CA −0.797 4.584 3.234 6 GLU HN 0.545 4.337 1.543 6 GLU HA −0.766 4.194 4.238 6 GLU C −2.174 4.334 2.625 6 GLU O −3.182 4.404 3.326 6 GLU CB −0.517 6.066 3.324 6 GLU CG −1.394 6.792 4.342 6 GLU CD −1.241 6.210 5.741 6 GLU OE1 −2.246 5.654 6.235 6 GLU OE2 −0.124 6.332 6.290 6 GLU HB1 0.541 6.185 3.551 6 GLU HB2 −0.707 6.444 2.332 6 GLU HG1 −1.101 7.841 4.360 6 GLU HG2 −2.436 6.722 4.036 7 TRP N −2.229 4.100 1.315 7 TRP CA −3.460 4.217 0.555 7 TRP HN −1.368 3.977 0.804 7 TRP HA −4.317 4.129 1.222 7 TRP C −3.504 3.121 −0.491 7 TRP O −4.454 2.344 −0.558 7 TRP CB −3.485 5.577 −0.150 7 TRP HB1 −4.435 5.670 −0.675 7 TRP HB2 −3.431 6.359 0.607 7 TRP CG −2.379 5.797 −1.141 7 TRP CD1 −1.059 5.740 −0.857 7 TRP CD2 −2.452 6.056 −2.579 7 TRP NE1 −0.316 5.931 −1.995 7 TRP CE2 −1.127 6.116 −3.086 7 TRP HD1 −0.629 5.529 0.104 7 TRP HE1 0.688 5.926 −2.054 7 TRP CE3 −3.486 6.229 −3.517 7 TRP HE3 −4.514 6.191 −3.189 7 TRP CZ2 −0.832 6.315 −4.430 7 TRP HZ2 0.208 6.311 −4.723 7 TRP CZ3 −3.203 6.453 −4.874 7 TRP HZ3 −4.014 6.590 −5.573 7 TRP CH2 −1.880 6.491 −5.336 7 TRP HH2 −1.673 6.653 −6.384 8 LEU N −2.458 3.080 −1.316 8 LEU CA −2.399 2.215 −2.463 8 LEU HN −1.741 3.788 −1.251 8 LEU HA −3.342 2.268 −2.987 8 LEU C −2.138 0.775 −2.047 8 LEU O −2.050 0.466 −0.861 B LEU CB −1.377 2.801 −3.420 8 LEU HB1 −1.919 3.553 −3.985 8 LEU HB2 −0.627 3.313 −2.838 8 LEU CG −0.697 1.810 −4.364 8 LEU HG −1.411 1.066 −4.715 8 LEU CD1 0.486 1.139 −3.660 8 LEU HD11 0.148 0.611 −2.770 8 LEU HD12 0.958 0.428 −4.336 8 LEU HD13 1.216 1.894 −3.367 8 LEU CD2 −0.166 2.597 −5.559 8 LEU HD21 0.377 1.929 −6.226 8 LEU HD22 −0.999 3.047 −6.099 8 LEU HD23 0.503 3.385 −5.211 9 PRO N −2.105 −0.108 −3.045 9 PRO CA −2.388 −1.520 −2.908 9 PRO CD −2.238 0.281 −4.432 9 PRO HA −3.411 −1.651 −2.592 9 PRO HD1 −1.244 0.463 −4.841 9 PRO HD2 −2.849 1.180 −4.534 9 PRO C −1.489 −2.327 −2.003 9 PRO O −0.712 −1.817 −1.200 9 PRO CB −2.321 −2.090 −4.308 9 PRO HB1 −2.906 −3.003 −4.418 9 PRO HB2 −1.278 −2.261 −4.524 9 PRO CG −2.874 −0.932 −5.115 9 PRO HG1 −3.943 −0.968 −4.924 9 PRO HG2 −2.647 −0.998 −6.179 10 CYS N −1.663 −3.631 −2.196 10 CYS CA −1.012 −4.692 −1.465 10 CYS HN −2.332 −3.890 −2.912 10 CYS HA −0.585 −4.387 −0.542 10 CYS C 0.010 −5.351 −2.349 10 CYS O 1.190 −5.013 −2.406 10 CYS CB −2.057 −5.730 −1.120 10 CYS SG −1.557 −6.937 0.133 10 CYS HB1 −2.248 −6.248 −2.047 10 CYS HB2 −2.961 −5.214 −0.820 10 CYS LG1 −2.185 −7.126 0.309 10 CYS LG2 −0.911 −6.990 −0.068 11 ALA N −0.563 −6.322 −3.032 11 ALA CA 0.071 −7.137 −4.047 11 ALA HN −1.541 −6.400 −2.791 11 ALA HA −0.700 −7.659 −4.614 11 ALA C 0.986 −8.164 −3.395 11 ALA O 1.316 −7.956 −2.208 11 ALA OXT 1.336 −9.138 −4.095 11 ALA CB 0.852 −6.232 −4.994 11 ALA HB1 1.630 −5.713 −4.434 11 ALA HB2 1.304 −6.831 −5.783 11 ALA HB3 0.172 −5.502 −5.433 END

TABLE III Orthogonal three dimensional coordinates in Ångströms for the phospholamban (1-36) peptide Residue Atom X Y Z 1 MET N −18.883 −3.493 9.020 1 MET CA −17.518 −3.957 8.653 1 MET HN1 −19.536 −4.279 9.119 1 MET HN2 −18.890 −2.989 9.914 1 MET HN3 −19.280 −2.863 8.314 1 MET HA −16.901 −3.038 8.626 1 MET C −17.415 −4.543 7.212 1 MET O −16.572 −4.081 6.439 1 MET CB −16.875 −4.826 9.772 1 MET HB1 −15.795 −4.924 9.547 1 MET HB2 −16.893 −4.265 10.726 1 MET CG −17.422 −6.248 10.031 1 MET SD −19.151 −6.241 10.562 1 MET CE −18.991 −5.887 12.325 1 MET HG1 −17.330 −6.874 9.124 1 MET HG2 −16.810 −6.758 10.798 1 MET HE1 −19.984 −5.878 12.809 1 MET HE2 −18.374 −6.655 12.827 1 MET HE3 −18.521 −4.900 12.492 2 GLU N −18.254 −5.533 6.842 2 GLU CA −18.265 −6.128 5.478 2 GLU HN −18.900 −5.856 7.571 2 GLU HA −17.210 −6.282 5.173 2 GLU C −18.948 −5.225 4.401 2 GLU O −19.754 −4.342 4.720 2 GLU CB −18.906 −7.547 5.541 2 GLU CG −20.416 −7.627 5.896 2 GLU CD −21.035 −8.987 5.590 2 GLU OE1 −21.495 −9.191 4.444 2 GLU OE2 −21.070 −9.854 6.489 2 GLU HB1 −18.746 −8.031 4.557 2 GLU HB2 −18.337 −8.184 6.246 2 GLU HG1 −20.571 −7.388 6.963 2 GLU HG2 −20.990 −6.864 5.338 3 LYS N −18.664 −5.521 3.116 3 LYS CA −19.464 −5.049 1.948 3 LYS HN −17.993 −6.291 3.013 3 LYS HA −19.008 −5.581 1.092 3 LYS C −19.248 −3.539 1.622 3 LYS O −18.370 −3.219 0.818 3 LYS CB −20.930 −5.587 1.997 3 LYS CG −21.709 −5.508 0.666 3 LYS CD −23.177 −5.990 0.736 3 LYS CE −23.411 −7.513 0.856 3 LYS NZ −23.320 −8.021 2.243 3 LYS HB1 −20.905 −6.644 2.322 3 LYS HB2 −21.495 −5.058 2.788 3 LYS HG1 −21.711 −4.458 0.320 3 LYS HG2 −21.169 −6.068 −0.122 3 LYS HD1 −23.726 −5.441 1.525 3 LYS HD2 23.662 −5.662 −0.204 3 LYS HE1 −24.420 −7.750 0.465 3 LYS HE2 −22.711 −8.069 0.201 3 LYS HZ1 −22.376 −7.928 2.639 3 LYS HZ2 −23.954 −7.523 2.880 3 LYS HZ3 −23.558 −9.017 2.311 4 VAL N −20.017 −2.625 2.249 4 VAL CA −19.844 −1.150 2.084 4 VAL HN −20.672 −3.020 2.932 4 VAL HA −19.723 −0.979 0.995 4 VAL C −18.532 −0.595 2.734 4 VAL O −17.763 0.075 2.042 4 VAL CB −21.166 −0.392 2.460 4 VAL HB −21.981 −0.865 1.880 4 VAL CG1 −21.148 1.087 2.010 4 VAL HG11 −22.125 1.579 2.173 4 VAL HG12 −20.389 1.679 2.555 4 VAL HG13 −20.921 1.182 0.931 4 VAL CG2 −21.594 0.469 3.946 4 VAL HG21 −22.587 −0.009 4.106 4 VAL HG22 −21.672 −1.514 4.297 4 VAL HG23 −20.886 0.051 4.615 5 GLN N −18.257 −0.895 4.022 5 GLN CA −16.969 −0.532 4.685 5 GLN HN −18.970 −1.467 4.487 5 GLN HA −16.753 0.525 4.431 5 GLN C −15.708 −1.326 4.214 5 GLN O −14.609 −0.764 4.263 5 GLN CB −17.126 −0.595 6.230 5 GLN HB1 −16.134 −0.491 6.711 5 GLN HB2 −17.470 −1.605 6.519 5 GLN CG −18.072 0.452 6.870 5 GLN HG1 −19.093 0.350 6.454 5 GLN HG2 −18.189 0.209 7.943 5 GLN CD −17.577 1.906 6.777 5 GLN OE1 −16.699 2.331 7.525 5 GLN NE2 −18.118 2.697 5.865 5 GLN HE21 −17.754 3.655 5.830 5 GLN HE22 −18.828 2.281 5.254 6 TYR N −15.837 −2.578 3.722 6 TYR CA −14.754 −3.255 2.953 6 TYR HN −16.798 −2.934 3.726 6 TYR HA −13.836 −3.179 3.569 6 TYR C −14.429 −2.578 1.577 6 TYR O −13.246 −2.405 1.284 6 TYR CB −15.073 −4.771 2.823 6 TYR HB1 −15.450 −5.161 3.789 6 TYR HB2 −15.922 −4.917 2.126 6 TYR CG −13.870 −5.631 2.391 6 TYR CD1 −12.947 −6.081 3.342 6 TYR HD1 −13.093 −5.867 4.391 6 TYR CD2 −13.656 −5.919 1.038 6 TYR HD2 −14.351 −5.571 0.287 6 TYR CE1 −11.820 −6.795 2.944 6 TYR HE1 −11.109 −7.135 3.683 6 TYR CE2 −12.526 −6.633 0.642 6 TYR HE2 −12.364 −6.840 −0.406 6 TYR CZ −11.608 −7.066 1.594 6 TYR OH −10.486 −7.749 1.203 6 TYR HH −10.543 −7.928 0.261 7 LEU N −15.435 −2.177 0.768 7 LEU CA −15.228 −1.333 −0.448 7 LEU HN −16.377 −2.392 1.118 7 LEU HA −14.505 −1.879 −1.083 7 LEU C −14.618 0.088 −0.187 7 LEU O −13.755 0.514 −0.959 7 LEU CB −16.568 −1.276 −1.239 7 LEU HB1 −16.964 −2.304 −1.362 7 LEU HB2 −17.320 −0.763 −0.607 7 LEU CG −16.545 −0.600 −2.641 7 LEU HG −16.134 0.421 −2.532 7 LEU CD1 −17.977 −0.449 −3.189 7 LEU HD11 −18.471 −1.427 −3.341 7 LEU HD12 −18.616 0.136 −2.501 7 LEU HD13 −17.989 0.081 −4.159 7 LEU CD2 −15.670 −1.352 −3.665 7 LEU HD21 −16.014 −2.391 3.823 7 LEU HD22 −15.676 −0.852 −4.652 7 LEU HD23 −14.613 −1.398 −3.347 8 THR N −15.020 0.793 0.895 8 THR CA −14.337 2.035 1.379 8 THR HN −15.786 0.362 1.425 8 THR HA −14.401 2.775 0.558 8 THR C −12.813 1.822 1.687 8 THR O −11.983 2.555 1.144 8 THR CB −15.125 2.633 2.591 8 THR OG1 −16.503 2.806 2.270 8 THR HB −15.061 1.931 3.445 8 THR HG1 −16.535 3.486 1.594 8 THR CG2 −14.620 4.006 3.070 8 THR HG21 −14.652 4.764 2.265 8 THR HG22 −15.233 4.389 3.908 8 THR HG23 −13.579 3.955 3.436 9 ARG N −12.454 0.800 2.491 9 ARG CA −11.040 0.367 2.694 9 ARG HN −13.242 0.262 2.868 9 ARG HA −10.475 1.248 3.056 9 ARG C −10.279 −0.141 1.422 9 ARG O −9.068 0.074 1.342 9 ARG CB −10.986 −0.704 3.816 9 ARG CG −11.336 −0.195 5.239 9 ARG CD −11.278 −1.278 6.331 9 ARG NE −12.399 −2.249 6.225 9 ARG CZ −12.453 −3.428 6.870 9 ARG NH1 −13.518 −4.178 6.704 9 ARG NH2 −11.493 −3.881 7.666 9 ARG HB1 −9.966 −1.132 3.864 9 ARG HB2 −11.641 −1.555 3.549 9 ARG HG1 −10.627 0.611 5.509 9 ARG HG2 −12.331 0.292 5.247 9 ARG HD1 −10.296 −1.790 6.290 9 ARG HD2 −11.320 −0.790 7.325 9 ARG HE −13.225 −2.039 5.652 9 ARG HH12 −14.259 −3.806 6.101 9 ARG HH11 −13.535 −5.071 7.209 9 ARG HH21 −10.677 −3.270 7.781 9 ARG HH22 −11.642 −4.793 8.108 10 SER N −10.946 −0.787 0.443 10 SER CA −10.354 −1.132 −0.884 10 SER HN −11.942 −0.946 0.641 10 SER HA 9.439 −1.724 −0.697 10 SER C −9.924 0.093 −1.755 10 SER O −8.816 0.081 −2.300 10 SER CB −11.306 −2.070 −1.661 10 SER OG −11.499 −3.303 −0.971 10 SER HB1 −12.283 −1.585 −1.840 10 SER HB2 −10.895 −2.294 −2.663 10 SER HG −12.151 −3.796 −1.475 11 ALA N −10.757 1.151 −1.848 11 ALA CA −10.344 2.469 −2.403 11 ALA HN −11.651 1.031 −1.357 11 ALA HA −9.966 2.296 −3.429 11 ALA C −9.219 3.223 −1.619 11 ALA O −8.321 3.776 −2.259 11 ALA CB −11.608 3.341 −2.539 11 ALA HB1 −12.075 3.558 −1.559 11 ALA HB2 −11.379 4.314 −3.012 11 ALA HB3 −12.378 2.857 −3.170 12 ILE N −9.242 3.226 −0.266 12 ILE CA −8.172 3.838 0.586 12 ILE HN −10.056 2.754 0.145 12 ILE HA −8.006 4.865 0.200 12 ILE C −6.795 3.099 0.438 12 ILE O −5.794 3.779 0.207 12 ILE CB −8.658 4.011 2.076 12 ILE HB −8.948 3.006 2.440 12 ILE CG1 −9.901 4.950 2.214 12 ILE HG11 −10.620 4.757 1.398 12 ILE HG12 −9.602 6.005 2.066 12 ILE CG2 −7.544 4.533 3.028 12 ILE HG21 −7.887 4.618 4.075 12 ILE HG22 −6.669 3.857 3.055 12 ILE HG23 −7.174 5.529 2.721 12 ILE CD1 −10.686 4.819 3.530 12 ILE HD11 −11.582 5.467 3.523 12 ILE HD12 −11.037 3.782 3.694 12 ILE HD13 −10.086 5.112 4.410 13 ARG N −6.728 1.753 0.563 13 ARG CA −5.468 0.976 0.354 13 ARG HN −7.628 1.294 0.749 13 ARG HA −4.726 1.433 1.041 13 ARG C 4.830 1.090 −1.073 13 ARG O −3.613 1.260 −1.173 13 ARG CB −5.630 −0.486 0.871 13 ARG CG −6.342 −1.498 −0.063 13 ARG CD −6.640 −2.883 0.549 13 ARG NE −7.896 −2.883 1.345 13 ARG CZ −8.627 −3.976 1.626 13 ARG NH1 −8.236 −5.216 1.363 13 ARG NH2 −9.800 −3.810 2.198 13 ARG HB1 −6.139 −0.472 1.855 13 ARG HB2 −4.622 −0.886 1.095 13 ARG HG1 −7.266 −1.050 −0.471 13 ARG HG2 −5.699 −1.654 −0.950 13 ARG HD1 −6.722 −3.609 −0.283 13 ARG HD2 −5.789 −3.231 1.168 13 ARG HE −8.340 −1.998 1.613 13 ARG HH12 −7.314 −5.315 0.927 13 ARG HH11 −8.879 −5.974 1.620 13 ARG HH21 −10.096 −2.844 2.364 13 ARG HH22 −10.347 −4.658 2.382 14 ARG N −5.647 1.040 −2.150 14 ARG CA −5.205 1.316 −3.547 14 ARG HN −6.640 0.917 −1.918 14 ARG HA −4.382 0.609 −3.774 14 ARG C −4.654 2.762 −3.783 14 ARG O −3.574 2.899 −4.362 14 ARG CB −6.387 0.954 −4.492 14 ARG CG −6.046 0.936 −6.002 14 ARG CD −7.241 0.641 −6.935 14 ARG NE −7.781 −0.743 −6.818 14 ARG CZ −7.326 −1.813 −7.495 14 ARG NH1 −6.304 −1.776 −8.341 14 ARG NH2 −7.927 −2.967 −7.304 14 ARG HB1 −6.779 −0.047 −4.223 14 ARG HB2 −7.232 1.648 −4.313 14 ARG HG1 −5.635 1.922 −6.287 14 ARG HG2 −5.227 0.217 −6.196 14 ARG HD1 −8.058 1.355 −6.720 14 ARG HD2 −6.959 0.862 −7.983 14 ARG HE −8.576 −0.946 −6.202 14 ARG HH12 −5.856 −0.864 −8.466 14 ARG HH11 −6.046 −2.656 −8.800 14 ARG HH21 −8.716 −2.973 −6.649 14 ARG HH22 −7.566 −3.769 −7.830 15 ALA N −5.366 3.815 −3.329 15 ALA CA −4.859 5.215 −3.352 15 ALA HN −6.249 3.572 −2.865 15 ALA HA −4.610 5.460 −4.404 15 ALA C −3.580 5.502 −2.503 15 ALA O −2.687 6.192 −2.996 15 ALA CB −6.019 6.148 −2.948 15 ALA HB1 −5.723 7.211 −3.012 15 ALA HB2 6.898 6.024 −3.608 15 ALA HB3 −6.360 5.965 −1.911 16 SER N −3.471 4.962 −1.270 16 SER CA −2.253 5.080 −0.420 16 SER HN −4.293 4.425 −0.965 16 SER HA −2.050 6.162 −0.292 16 SER C −0.958 4.438 −1.011 16 SER O 0.081 5.105 −1.033 16 SER CB −2.595 4.527 0.984 16 SER OG −1.533 4.766 1.904 16 SER HB1 −2.808 3.441 0.942 16 SER HB2 −3.513 5.000 1.382 16 SER HG −0.749 4.360 1.526 17 THR N −1.011 3.178 −1.503 17 THR CA 0.124 2.551 −2.246 17 THR HN −1.934 2.731 −1.438 17 THR HA 1.023 2.737 −1.625 17 THR C 0.453 3.189 −3.638 17 THR O 1.637 3.295 −3.969 17 THR CB −0.014 0.998 −2.268 17 THR OG1 1.246 0.419 −2.593 17 THR HB −0.270 0.656 −1.245 17 THR HG1 1.437 0.690 −3.494 17 THR CG2 −1.058 0.403 −3.230 17 THR HG21 −1.179 −0.683 −3.070 17 THR HG22 −2.050 0.867 −3.099 17 THR HG23 −0.770 0.546 −4.287 18 ILE N −0.556 3.629 −4.427 18 ILE CA −0.333 4.400 −5.692 18 ILE HN −1.497 3.496 −4.036 18 ILE HA 0.698 4.211 −6.053 18 ILE C −0.421 5.946 −5.379 18 ILE O −1.236 6.672 −5.957 18 ILE CB −1.288 3.908 −6.652 18 ILE HB −2.305 4.271 −6.603 18 ILE CG1 −1.395 2.357 −7.037 18 ILE HG11 −1.526 1.871 −6.054 18 ILE HG12 −0.444 1.948 −7.427 18 ILE CG2 −0.883 4.538 −8.215 18 ILE HG21 −0.844 5.641 −8.182 18 ILE HG22 0.115 4.193 −8.547 18 ILE HG23 −1.597 4.290 −9.020 18 ILE CD1 −2.570 1.867 −7.901 18 ILE HD11 −2.470 2.172 −8.958 18 ILE HD12 −2.641 0.764 −7.888 18 ILE HD13 −3.536 2.260 −7.531 19 GLU N 0.446 6.441 −4.470 19 GLU CA 0.634 7.888 −4.165 19 GLU HN 1.033 5.726 −4.025 19 GLU HA 0.850 8.416 −5.116 19 GLU C 1.890 7.939 −3.246 19 GLU O 1.773 7.912 −2.015 19 GLU CB −0.615 8.561 −3.518 19 GLU CG −0.502 10.091 −3.331 19 GLU CD −1.757 10.709 −2.714 19 GLU OE1 −1.821 10.833 −1.471 19 GLU OE2 −2.681 11.079 −3.471 19 GLU HB1 −1.509 8.364 −4.140 19 GLU HB2 −0.836 8.082 −2.544 19 GLU HG1 0.364 10.339 −2.690 19 GLU HG2 −0.306 10.582 −4.302 20 MET N 3.097 7.953 3.849 20 MET CA 4.367 7.766 −3.099 20 MET HN 3.066 7.947 −4.874 20 MET HA 4.229 8.109 −2.058 20 MET C 5.500 8.612 −3.764 20 MET O 5.912 8.250 −4.873 20 MET CB 4.774 6.264 −3.011 20 MET HB1 4.730 5.784 −4.006 20 MET HB2 5.837 6.193 −2.714 20 MET CG 3.968 5.437 −1.993 20 MET SD 4.791 3.860 −1.711 20 MET CE 4.009 3.366 −0.164 20 MET HG1 3.884 5.980 −1.034 20 MET HG2 2.935 5.259 −2.347 20 MET HE1 4.407 2.394 0.179 20 MET HE2 4.198 4.113 0.628 20 MET HE3 2.916 3.266 −0.289 21 PRO N 6.082 9.682 −3.136 21 PRO CA 7.307 10.353 −3.661 21 PRO CD 5.577 10.289 −1.885 21 PRO HA 7.190 10.566 −4.742 21 PRO HD1 5.491 9.562 −1.057 21 PRO HD2 4.577 10.737 −2.051 21 PRO C 8.610 9.505 −3.466 21 PRO O 8.564 8.355 −3.015 21 PRO CB 7.264 11.689 −2.884 21 PRO HB1 8.254 12.168 −2.762 21 PRO HB2 6.636 12.421 −3.431 21 PRO CG 6.612 11.360 −1.542 21 PRO HG1 6.162 12.247 −1.057 21 PRO HG2 7.367 10.953 −0.842 22 GLN N 9.775 10.079 −3.825 22 GLN CA 11.099 9.383 −3.763 22 GLN HN 9.684 11.026 −4.202 22 GLN HA 11.033 8.583 −4.525 22 GLN C 11.482 8.638 −2.439 22 GLN O 11.949 7.500 −2.513 22 GLN CB 12.223 10.322 −4.282 22 GLN HB1 13.148 9.727 −4.407 22 GLN HB2 11.966 10.640 −5.311 22 GLN CG 12.550 11.578 −3.435 22 GLN HG1 11.630 12.168 −3.268 22 GLN HG2 12.884 11.281 −2.422 22 GLN CD 13.588 12.498 −4.093 22 GLN OE1 13.260 13.333 −4.933 22 GLN NE2 14.855 12.373 −3.736 22 GLN HE21 15.067 11.660 −3.030 22 GLN HE22 15.516 13.007 −4.196 23 GLN N 11.241 9.236 −1.255 23 GLN CA 11.413 8.552 0.061 23 GLN HN 10.841 10.178 −1.328 23 GLN HA 12.430 8.113 0.051 23 GLN C 10.448 7.350 0.351 23 GLN O 10.910 6.324 0.858 23 GLN CB 11.447 9.600 1.208 23 GLN HB1 12.280 10.306 1.013 23 GLN HB2 11.743 9.086 2.143 23 GLN CG 10.154 10.415 1.475 23 GLN HG1 9.839 10.931 0.549 23 GLN HG2 9.316 9.735 1.719 23 GLN CD 10.320 11.475 2.574 23 GLN OE1 10.799 12.580 2.329 23 GLN NE2 9.928 11.173 3.800 23 GLN HE21 9.539 10.235 3.942 23 GLN HE22 10.049 11.909 4.503 24 ALA N 9.143 7.463 0.030 24 ALA CA 8.159 6.359 0.204 24 ALA HN 8.886 8.352 −0.413 24 ALA HA 8.289 5.956 1.227 24 ALA C 8.290 5.147 −0.774 24 ALA O 8.102 4.010 −0.329 24 ALA CB 6.748 6.969 0.163 24 ALA HB1 6.615 7.761 0.924 24 ALA HB2 6.522 7.421 −0.821 24 ALA HB3 5.969 6.209 0.360 25 ARG N 8.632 5.358 −2.064 25 ARG CA 9.043 4.252 −2.981 25 ARG HN 8.743 6.347 −2.322 25 ARG HA 8.300 3.441 −2.842 25 ARG C 10.430 3.587 −2.668 25 ARG O 10.540 2.365 −2.801 25 ARG CB 8.889 4.651 −4.473 25 ARG CG 9.786 5.799 −5.012 25 ARG CD 10.177 5.685 −6.502 25 ARG NE 11.091 4.541 −6.782 25 ARG CZ 12.421 4.541 −6.578 25 ARG NH1 13.108 5.603 −6.180 25 ARG NH2 13.079 3.421 −6.783 25 ARG HB1 7.831 4.908 4.677 25 ARG HB2 9.054 3.736 −5.072 25 ARG HG1 9.259 6.756 −4.857 25 ARG HG2 10.708 5.894 −4.408 25 ARG HD1 9.264 5.572 −7.115 25 ARG HD2 10.627 6.636 −6.847 25 ARG HE 10.720 3.637 −7.092 25 ARG HH12 12.567 6.460 −6.027 25 ARG HH11 14.116 5.475 −6.041 25 ARG HH21 12.529 2.612 −7.087 25 ARG HH22 14.087 3.441 −6.595 26 GLN N 11.453 4.350 −2.215 26 GLN CA 12.697 3.779 −1.612 26 GLN HN 11.240 5.353 −2.152 26 GLN HA 13.138 3.102 −2.365 26 GLN C 12.484 2.907 −0.334 26 GLN O 13.148 1.878 −0.206 26 GLN CB 13.749 4.894 −1.344 26 GLN HB1 13.273 5.724 −0.787 26 GLN HB2 14.530 4.520 −0.653 26 GLN CG 14.472 5.467 −2.589 26 GLN HG1 15.030 6.376 −2.295 26 GLN HG2 13.724 5.828 −3.317 26 GLN CD 15.422 4.491 −3.305 26 GLN OE1 15.071 3.875 −4.309 26 GLN NE2 16.638 4.327 −2.815 26 GLN HE21 16.862 4.843 −1.957 26 GLN HE22 17.228 3.639 −3.294 27 LYS N 11.548 3.264 0.572 27 LYS CA 11.074 2.367 1.667 27 LYS HN 11.088 4.160 0.371 27 LYS HA 11.940 2.194 2.336 27 LYS C 10.559 0.961 1.203 27 LYS O 10.956 −0.041 1.801 27 LYS CB 10.012 3.154 2.484 27 LYS CG 9.566 2.501 3.813 27 LYS CD 8.426 3.241 4.552 27 LYS CE 6.988 2.966 4.055 27 LYS NZ 6.636 3.687 2.812 27 LYS HB1 9.132 3.324 1.842 27 LYS HB2 10.393 4.168 2.720 27 LYS HG1 9.272 1.447 3.652 27 LYS HG2 10.446 2.449 4.483 27 LYS HD1 8.466 2.914 5.609 27 LYS HD2 8.630 4.328 4.599 27 LYS HE1 6.828 1.878 3.918 27 LYS HE2 6.273 3.264 4.847 27 LYS HZ1 6.751 4.702 2.914 27 LYS HZ2 7.225 3.398 2.022 27 LYS HZ3 5.663 3.522 2.532 28 LEU N 9.719 0.878 0.145 28 LEU CA 9.260 −0.418 −0.438 28 LEU HN 9.490 1.779 0.290 28 LEU HA 8.796 −0.997 0.384 28 LEU C 10.403 −1.321 −1.004 28 LEU O 10.505 −2.475 −0.581 28 LEU CB 8.156 −0.187 −1.513 28 LEU HB1 8.584 0.438 −2.322 28 LEU HB2 7.934 −1.155 −2.004 28 LEU CG 6.803 0.435 −1.064 28 LEU HG 7.002 1.418 −0.596 28 LEU CD1 5.909 0.683 −2.295 28 LEU HD11 5.692 −0.251 −2.848 28 LEU HD12 4.935 1.125 −2.018 28 LEU HD13 6.384 1.382 −3.009 28 LEU CD2 6.044 −0.436 −0.042 28 LEU HD21 5.068 0.007 0.230 28 LEU HD22 5.844 −1.452 −0.431 28 LEU HD23 6.607 −0.550 0.901 29 GLN N 11.255 −0.816 −1.925 29 GLN CA 12.406 −1.595 −2.475 29 GLN HN 11.082 0.162 −2.182 29 GLN HA 11.991 −2.584 −2.755 29 GLN C 13.567 −1.934 −1.484 29 GLN O 14.147 −3.014 −1.607 29 GLN CB 12.883 −1.003 −3.833 29 GLN HB1 13.599 −1.706 −4.301 29 GLN HB2 12.019 −1.021 −4.524 29 GLN CG 13.475 0.432 −3.883 29 GLN HG1 12.803 1.117 −3.337 29 GLN HG2 13.438 0.795 −4.926 29 GLN CD 14.910 0.617 −3.360 29 GLN OE1 15.141 1.212 −2.310 29 GLN NE2 15.908 0.140 −4.084 29 GLN HE21 15.657 −0.353 −4.946 29 GLN HE22 16.847 0.271 −3.695 30 ASN N 13.883 −1.064 −0.500 30 ASN CA 14.859 −1.363 0.589 30 ASN HN 13.357 −0.182 −0.525 30 ASN HA 15.789 −1.718 0.103 30 ASN C 14.394 −2.487 1.576 30 ASN O 15.180 −3.393 1.865 30 ASN CB 15.209 −0.024 1.297 30 ASN HB1 14.313 0.381 1.811 30 ASN HB2 15.459 0.741 0.538 30 ASN CG 16.411 −0.079 2.257 30 ASN OD1 17.565 −0.101 1.835 30 ASN ND2 16.175 −0.094 3.557 30 ASN HD21 15.192 −0.090 3.848 30 ASN HD22 17.001 −0.122 4.163 31 LEU N 13.133 −2.449 2.059 31 LEU CA 12.510 −3.577 2.815 31 LEU HN 12.579 −1.645 1.742 31 LEU HA 13.171 −3.801 3.673 31 LEU C 12.370 −4.919 2.020 31 LEU O 12.617 −5.979 2.598 31 LEU CB 11.135 −3.137 3.397 31 LEU HB1 10.484 −2.835 2.550 31 LEU HB2 10.622 −4.020 3.828 31 LEU CG 11.136 −2.012 4.471 31 LEU HG 11.710 −1.150 4.082 31 LEU CD1 9.702 −1.513 4.733 31 LEU HD11 9.051 −2.309 5.141 31 LEU HD12 9.685 −0.673 5.453 31 LEU HD13 9.225 −1.143 3.806 31 LEU CD2 11.790 −2.446 5.800 31 LEU HD21 11.766 −1.636 6.552 31 LEU HD22 11.283 −3.323 6.245 31 LEU HD23 12.853 −2.715 5.665 32 PHE N 12.006 −4.880 0.720 32 PHE CA 11.945 −6.085 −0.153 32 PHE HN 11.808 −3.940 0.359 32 PHE HA 11.330 −6.832 0.380 32 PHE C 13.325 −6.763 −0.442 32 PHE O 13.428 −7.981 −0.273 32 PHE CB 11.156 −5.718 −1.445 32 PHE HB1 10.236 −5.162 −1.176 32 PHE HB2 11.739 −4.989 −2.041 32 PHE CG 10.748 −6.916 −2.322 32 PHE CD1 11.529 −7.286 −3.422 32 PHE HD1 12.424 −6.733 −3.671 32 PHE CD2 9.607 −7.664 −2.009 32 PHE HD2 8.994 −7.398 −1.160 32 PHE CE1 11.181 8.394 −4.190 32 PHE HE1 11.800 −8.686 −5.026 32 PHE CE2 9.262 −8.773 −2.778 32 PHE HE2 8.387 −9.355 −2.525 32 PHE CZ 10.049 −9.138 −3.867 32 PHE HZ 9.787 −10.004 −4.457 33 ILE N 14.353 −6.004 −0.883 33 ILE CA 15.663 −6.564 −1.345 33 ILE HN 14.134 −5.006 −0.980 33 ILE HA 15.384 −7.289 −2.133 33 ILE C 16.495 −7.409 −0.317 33 ILE O 17.181 −8.344 −0.739 33 ILE CB 16.489 −5.449 −2.086 33 ILE HB 15.776 −4.903 −2.735 33 ILE CG1 17.557 −6.044 −3.052 33 ILE HG11 17.119 −6.899 −3.603 33 ILE HG12 18.393 −6.481 −2.473 33 ILE CG2 17.113 −4.397 −1.130 33 ILE HG21 17.525 −3.530 −1.679 33 ILE HG22 16.366 −3.996 −0.425 33 ILE HG23 17.934 −4.823 −0.524 33 ILE CD1 18.119 −5.067 −4.098 33 ILE HD11 17.319 −4.642 −4.731 33 ILE HD12 18.660 −4.224 −3.631 33 ILE HD13 18.834 −5.575 −4.772 34 ASN N 16.432 −7.113 1.000 34 ASN CA 17.066 −7.958 2.057 34 ASN HN 15.817 −6.323 1.227 34 ASN HA 18.139 −8.016 1.783 34 ASN C 16.596 −9.450 2.131 34 ASN O 17.449 −10.334 2.262 34 ASN CB 17.063 −7.233 3.433 34 ASN HB1 17.629 −7.850 4.158 34 ASN HB2 17.675 −6.313 3.346 34 ASN CG 15.701 −6.904 4.084 34 ASN OD1 14.944 −7.786 4.489 34 ASN ND2 15.366 −5.635 4.221 34 ASN HD21 16.007 −4.942 3.822 34 ASN HD22 14.441 −5.462 4.626 35 PHE N 15.282 −9.732 2.018 35 PHE CA 14.756 −11.120 1.861 35 PHE HN 14.679 −8.909 1.899 35 PHE HA 15.444 −11.796 2.407 35 PHE C 14.743 −11.669 0.395 35 PHE O 15.062 −12.848 0.209 35 PHE CB 13.404 −11.302 2.611 35 PHE HB1 13.580 −11.112 3.689 35 PHE HB2 13.142 −12.378 2.592 35 PHE CG 12.173 −10.489 2.152 35 PHE CD1 11.351 −10.970 1.126 35 PHE HD1 11.594 −11.891 0.615 35 PHE CD2 11.830 −9.300 2.804 35 PHE HD2 12.449 −8.910 3.599 35 PHE CE1 10.209 −10.267 0.752 35 PHE HE1 9.583 −10.638 −0.047 35 PHE CE2 10.675 −8.610 2.442 35 PHE HE2 10.412 −7.694 2.952 35 PHE CZ 9.867 −9.092 1.417 35 PHE HZ 8.977 −8.551 1.131 36 CYS N 14.361 −10.862 −0.617 36 CYS CA 14.287 −11.298 −2.032 36 CYS C 14.877 −10.182 −2.921 36 CYS O 16.060 −10.297 −3.312 36 CYS CB 12.828 −11.666 −2.386 36 CYS SG 12.713 −12.287 −4.099 36 CYS OXT 14.177 −9.193 −3.237 36 CYS HN 14.138 −9.897 −0.344 36 CYS HA 14.907 −12.202 −2.195 36 CYS HB1 12.450 −12.455 −1.710 36 CYS HB2 12.149 −10.800 −2.263 36 CYS HG 12.819 −11.106 −4.704 END

TABLE IV Orthogonal three dimensional coordinates in Ångströms for the cP226 · phospholamban (1-36) complex Residue Atom X Y Z 1 MET N −18.366 −10.441 5.382 1 MET CA −16.968 −10.052 5.756 1 MET HN1 −18.363 −11.296 4.808 1 MET HN2 −18.964 −10.642 6.192 1 MET HN3 −18.836 −9.728 4.811 1 MET HA −17.022 −9.109 6.345 1 MET C −16.058 −9.653 4.544 1 MET O −15.491 −8.562 4.547 1 MET CB −16.367 −11.107 6.732 1 MET HB1 −15.418 −10.692 7.133 1 MET HB2 −16.999 −11.196 7.638 1 MET CG −16.048 −12.534 6.208 1 MET SD −17.501 −13.438 5.624 1 MET CE −18.199 −13.998 7.185 1 MET HG1 −15.303 −12.501 5.387 1 MET HG2 −15.555 −13.137 6.997 1 MET HE1 −19.124 −14.578 7.010 1 MET HE2 −17.490 −14.662 7.714 1 MET HE3 −18.445 −13.157 7.857 2 GLU N −15.964 −10.507 3.518 2 GLU CA −15.197 −10.254 2.269 2 GLU HN −16.431 −11.415 3.613 2 GLU HA −14.384 −9.526 2.462 2 GLU C −16.086 −9.579 1.149 2 GLU O −16.809 −8.614 1.422 2 GLU CB −14.496 −11.624 1.943 2 GLU CG −15.304 −12.969 1.947 2 GLU CD −16.679 −12.989 1.312 2 GLU OE1 −16.770 −13.228 0.092 2 GLU OE2 −17.689 −12.746 2.009 2 GLU HB1 −13.980 −11.532 0.967 2 GLU HB2 −13.654 −11.750 2.652 2 GLU HG1 −14.713 −13.761 1.451 2 GLU HG2 −15.430 −13.335 2.980 3 LYS N −16.030 −10.063 −0.108 3 LYS CA −16.999 −9.726 −1.196 3 LYS HN −15.594 −10.995 −0.096 3 LYS HA −16.597 −10.266 −2.076 3 LYS C −16.983 −8.231 −1.670 3 LYS O −16.139 −7.854 −2.488 3 LYS CB −18.379 −10.400 −0.889 3 LYS CG −19.212 −10.831 −2.119 3 LYS CD −20.381 −11.791 −1.776 3 LYS CE −20.044 −13.300 −1.688 3 LYS NZ −19.369 −13.685 −0.411 3 LYS HB1 −18.203 −11.293 −0.268 3 LYS HB2 −18.978 −9.753 −0.222 3 LYS HG1 −19.611 −9.917 −2.608 3 LYS HG2 −18.563 −11.290 −2.893 3 LYS HD1 −20.925 −11.444 −0.874 3 LYS HD2 −21.132 −11.674 −2.584 3 LYS HE1 −20.986 −13.883 −1.807 3 LYS HE2 −19.429 −13.605 −2.567 3 LYS HZ1 −18.360 −13.394 −0.340 3 LYS HZ2 −19.747 −13.259 0.445 3 LYS HZ3 −19.300 14.692 −0.225 4 VAL N −17.850 −7.370 −1.113 4 VAL CA −17.729 −5.883 −1.250 4 VAL HN −18.368 −7.786 −0.332 4 VAL HA −17.617 −5.678 −2.335 4 VAL C −16.444 −5.249 −0.593 4 VAL O −15.841 −4.361 −1.194 4 VAL CB −19.085 −5.211 −0.839 4 VAL HB −19.895 −5.756 −1.368 4 VAL CG1 −19.192 −3.746 −1.314 4 VAL HG11 −20.191 −3.313 −1.113 4 VAL HG12 −18.450 −3.089 −0.822 4 VAL HG13 −19.028 −3.652 −2.405 4 VAL CG2 −19.423 −5.252 0.671 4 VAL HG21 −20.429 −4.840 0.877 4 VAL HG22 −19.412 −6.281 1.073 4 VAL HG23 −18.707 −4.660 1.273 5 GLN N −15.991 −5.716 0.586 5 GLN CA −14.681 −5.298 1.177 5 GLN HN −16.525 −6.517 0.946 5 GLN HA −14.601 −4.196 1.093 5 GLN C −13.383 −5.831 0.471 5 GLN O −12.357 −5.141 0.491 5 GLN CB −14.696 −5.643 2.692 5 GLN HB1 −13.684 −5.487 3.116 5 GLN HB2 −14.878 −6.728 2.817 5 GLN CG −15.703 −4.852 3.575 5 GLN HG1 −16.738 −4.985 3.209 5 GLN HG2 −15.711 −5.300 4.586 5 GLN CD −15.396 −3.363 3.762 5 GLN OE1 −14.647 −2.963 4.642 5 GLN NE2 −15.948 −2.495 2.953 5 GLN HE21 −15.630 −1.536 3.116 5 GLN HE22 −16.412 −2.871 2.123 6 TYR N −13.412 −7.004 −0.197 6 TYR CA −12.392 −7.346 −1.233 6 TYR HN −14.349 −7.420 −0.207 6 TYR HA −11.396 −7.186 −0.771 6 TYR C −12.416 −6.413 −2.498 6 TYR O −11.364 −5.894 −2.875 6 TYR CB −12.491 −8.863 −1.566 6 TYR HB1 −12.592 −9.455 −0.636 6 TYR HB2 −13.426 −9.070 −2.123 6 TYR CG −11.270 −9.381 −2.345 6 TYR CD1 −10.084 −9.668 −1.661 6 TYR HD1 −10.045 −9.609 −0.583 6 TYR CD2 −11.292 −9.461 −3.742 6 TYR HD2 −12.200 −9.241 −4.287 6 TYR CE1 −8.932 −10.001 −2.366 6 TYR HE1 −8.027 −10.232 −1.830 6 TYR CE2 −10.131 −9.785 −4.444 6 TYR HE2 −10.139 −9.832 −5.524 6 TYR CZ −8.947 −10.036 −3.755 6 TYR OH −7.791 −10.280 −4.452 6 TYR HH −7.019 −10.219 −3.861 7 LEU N −13.587 −6.154 −3.113 7 LEU CA −13.759 −5.074 −4.135 7 LEU HN −14.394 −6.657 −2.722 7 LEU HA −13.139 −5.360 −5.005 7 LEU C −13.271 −3.631 −3.733 7 LEU O −12.609 −2.977 −4.542 7 LEU CB −15.245 −5.133 −4.594 7 LEU HB1 −15.523 −6.180 −4.824 7 LEU HB2 −15.880 −4.860 −3.731 7 LEU CG −15.651 −4.252 −5.804 7 LEU HG −15.360 −3.200 −5.603 7 LEU CD1 −17.176 −4.286 −5.987 7 LEU HD11 −17.553 −5.304 −6.199 7 LEU HD12 −17.706 −3.921 −5.088 7 LEU HD13 −17.502 −3.639 −6.825 7 LEU CD2 −14.975 −4.703 −7.111 7 LEU HD21 −15.191 −5.760 −7.352 7 LEU HD22 −15.308 −4.098 −7.975 7 LEU HD23 −13.876 −4.592 −7.065 8 THR N −13.511 −3.164 −2.491 8 THR CA −12.882 −1.929 −1.922 8 THR HN −14.206 −3.711 −1.961 8 THR HA −13.236 −1.074 −2.530 8 THR C −11.312 −1.892 −2.013 8 THR O −10.767 −0.964 −2.613 8 THR CB −13.426 −1.715 −0.469 8 THR OG1 −14.849 −1.671 −0.441 8 THR HB −13.095 −2.565 0.160 8 THR HG1 −15.101 −0.841 −0.857 8 THR CG2 −12.988 −0.414 0.216 8 THR HG21 −13.230 0.484 −0.384 8 THR HG22 −13.473 −0.292 1.203 8 THR HG23 −11.898 −0.399 0.403 9 ARG N −10.582 −2.897 −1.486 9 ARG CA −9.100 −2.999 −1.688 9 ARG HN −11.154 −3.657 −1.099 9 ARG HA −8.665 −2.002 −1.470 9 ARG C −8.597 −3.341 −3.141 9 ARG O −7.489 −2.943 −3.504 9 ARG CB −8.480 −3.985 −0.662 9 ARG CG −8.679 −3.663 0.845 9 ARG CD −7.677 −4.331 1.815 9 ARG NE −7.723 −5.828 1.787 9 ARG CZ −6.925 −6.617 1.073 9 ARG NH1 −7.116 −7.891 1.115 9 ARG NH2 −5.961 −6.190 0.314 9 ARG HB1 −7.392 −4.020 −0.865 9 ARG HB2 −8.843 −5.012 −0.870 9 ARG HG1 −8.611 −2.565 0.992 9 ARG HG2 −9.719 −3.911 1.140 9 ARG HD1 −6.654 −3.934 1.650 9 ARG HD2 −7.914 −3.993 2.846 9 ARG HE −8.426 −6.349 2.319 9 ARG HH12 −7.864 −8.264 1.693 9 ARG HH11 −6.571 −8.401 0.386 9 ARG HH21 −5.791 −5.188 0.334 9 ARG HH22 −5.373 −6.910 −0.147 10 SER N −9.350 −4.086 −3.965 10 SER CA −9.062 −4.255 −5.423 10 SER HN −10.216 −4.451 −3.541 10 SER HA −7.998 −4.514 −5.543 10 SER C −9.237 −2.985 −6.326 10 SER O −8.384 −2.744 −7.184 10 SER CB −9.828 −5.503 −5.913 10 SER OG −9.313 −6.678 −5.275 10 SER HB1 −10.914 −5.399 −5.724 10 SER HB2 −9.719 −5.609 −7.011 10 SER HG −9.884 −7.422 −5.502 11 ALA N −10.260 −2.142 −6.107 11 ALA CA −10.294 −0.755 −6.648 11 ALA HN −10.941 −2.461 −5.403 11 ALA HA −10.105 −0.797 −7.740 11 ALA C −9.225 0.239 −6.059 11 ALA O −8.524 0.906 −6.827 11 ALA CB −11.743 −0.266 −6.454 11 ALA HB1 −12.024 −0.198 −5.385 11 ALA HB2 −11.891 0.739 −6.892 11 ALA HB3 −12.479 −0.934 −6.942 12 ILE N −9.063 0.325 −4.722 12 ILE CA −8.073 1.248 −4.069 12 ILE HN −9.733 −0.232 −4.175 12 ILE HA −8.213 2.243 −4.537 12 ILE C −6.563 0.911 −4.365 12 ILE O −5.785 1.854 −4.502 12 ILE CB −8.421 1.468 −2.546 12 ILE HB −8.473 0.468 −2.073 12 ILE CG1 −9.804 2.172 −2.347 12 ILE HG11 −10.558 1.710 −3.012 12 ILE HG12 −9.748 3.226 −2.688 12 ILE CG2 −7.349 2.290 −1.770 12 ILE HG21 −7.590 2.410 −0.699 12 ILE HG22 −6.350 1.816 −1.796 12 ILE HG23 −7.222 3.309 −2.187 12 ILE CD1 −10.379 2.121 −0.921 12 ILE HD11 −11.413 2.512 −0.890 12 ILE HD12 −10.405 1.088 −0.531 12 ILE HD13 −9.790 2.730 −0.211 13 ARG N −6.116 −0.357 −4.492 13 ARG CA −4.688 −0.677 −4.826 13 ARG HN −6.837 −1.075 −4.352 13 ARG HA −4.087 −0.227 −4.011 13 ARG C −4.064 −0.040 −6.124 13 ARG O −2.892 0.342 −6.094 13 ARG CB −4.446 −2.208 −4.706 13 ARG CG −4.985 −3.125 −5.840 13 ARG CD −4.694 −4.625 −5.629 13 ARG NE −5.635 −5.210 −4.631 13 ARG CZ −5.642 −6.473 −4.222 13 ARG NH1 −4.693 −7.326 −4.456 13 ARG NH2 −6.651 −6.890 −3.537 13 ARG HB1 −4.825 −2.556 −3.726 13 ARG HB2 −3.351 −2.360 −4.640 13 ARG HG1 −6.065 −2.948 −6.011 13 ARG HG2 −4.505 −2.820 −6.792 13 ARG HD1 −4.788 −5.161 −6.598 13 ARG HD2 −3.634 −4.753 −5.333 13 ARG HE −6.427 −4.657 −4.281 13 ARG HH12 −3.840 −6.971 −4.905 13 ARG HH11 −4.827 −8.262 −4.029 13 ARG HH21 −7.482 −6.302 −3.505 13 ARG HH22 −6.560 −7.869 −3.213 14 ARG N −4.825 0.102 −7.229 14 ARG CA −4.376 0.917 −8.401 14 ARG HN −5.808 −0.154 −7.074 14 ARG HA −3.272 0.844 −8.428 14 ARG C −4.656 2.464 −8.334 14 ARG O −3.866 3.230 −8.890 14 ARG CB −4.845 0.244 −9.719 14 ARG CG −4.019 0.701 −10.958 14 ARG CD −4.063 −0.202 −12.216 14 ARG NE −3.844 −1.670 −12.010 14 ARG CZ −2.795 −2.247 −11.427 14 ARG NH1 −1.732 −1.615 −11.038 14 ARG NH2 −2.842 −3.520 −11.225 14 ARG HB1 −4.739 −0.853 −9.604 14 ARG HB2 −5.927 0.412 −9.882 14 ARG HG1 −4.336 1.727 −11.239 14 ARG HG2 −2.961 0.842 −10.667 14 ARG HD1 −5.052 −0.063 −12.698 14 ARG HD2 −3.349 0.185 −12.973 14 ARG HE −4.569 −2.354 −12.237 14 ARG HH12 −1.739 −0.612 −11.189 14 ARG HH11 −1.056 −2.146 −10.443 14 ARG HH21 −3.658 −4.047 −11.522 14 ARG HH22 −2.019 −3.907 −10.697 15 ALA N −5.709 2.944 −7.642 15 ALA CA −5.801 4.374 −7.222 15 ALA HN −6.269 2.220 −7.179 15 ALA HA −5.765 5.005 −8.134 15 ALA C −4.644 4.893 −6.290 15 ALA O −4.074 5.946 −6.571 15 ALA CB −7.199 4.561 −6.603 15 ALA HB1 −7.394 5.627 −6.376 15 ALA HB2 −8.010 4.227 −7.279 15 ALA HB3 −7.305 4.011 −5.651 16 SER N −4.250 4.134 −5.248 16 SER CA −3.106 4.482 −4.352 16 SER HN −4.848 3.315 −5.069 16 SER HA −3.235 5.535 −4.049 16 SER C −1.638 4.397 −4.935 16 SER O −0.702 4.880 −4.297 16 SER CB −3.324 3.676 −3.050 16 SER OG −2.393 4.057 −2.031 16 SER HB1 −3.255 2.589 −3.240 16 SER HB2 −4.345 3.849 −2.656 16 SER HG −2.450 5.037 −1.916 17 THR N −1.403 3.876 −6.157 17 THR CA −0.201 4.263 −6.976 17 THR HN −2.258 3.512 −6.589 17 THR HA 0.636 4.460 −6.276 17 THR C −0.319 5.601 −7.802 17 THR O 0.712 6.218 −8.084 17 THR CB 0.310 3.069 −7.842 17 THR OG1 1.531 3.425 −8.481 17 THR HB 0.520 2.218 −7.163 17 THR HG1 1.382 4.296 −8.872 17 THR CG2 −0.615 2.566 −8.957 17 THR HG21 −0.136 1.754 −9.534 17 THR HG22 −1.545 2.157 −8.534 17 THR HG23 −0.896 3.364 −9.669 18 ILE N −1.523 6.028 −8.226 18 ILE CA −1.764 7.358 −8.891 18 ILE HN −2.302 5.493 −7.824 18 ILE HA −0.928 7.554 −9.592 18 ILE C −1.733 8.562 −7.864 18 ILE O −1.063 9.563 −8.116 18 ILE CB −3.077 7.284 −9.765 18 ILE HB −3.906 7.053 −9.065 18 ILE CG1 −3.060 6.171 −10.865 18 ILE HG11 −2.576 5.258 −10.472 18 ILE HG12 −2.417 6.477 −11.714 18 ILE CG2 −3.416 8.637 −10.450 18 ILE HG21 −3.540 9.455 −9.715 18 ILE HG22 −2.626 8.959 −11.154 18 ILE HG23 −4.364 8.600 −11.016 18 ILE CD1 −4.448 5.738 −11.380 18 ILE HD11 −4.987 6.560 −11.884 18 ILE HD12 −4.365 4.911 −12.110 18 ILE HD13 −5.090 5.375 −10.555 19 GLU N −2.426 8.437 −6.718 19 GLU CA −2.209 9.220 −5.456 19 GLU HN −2.954 7.556 −6.669 19 GLU HA −2.898 10.084 −5.466 19 GLU C −0.786 9.777 −5.056 19 GLU O −0.692 10.794 −4.362 19 GLU CB −2.714 8.196 −4.390 19 GLU CG −2.806 8.605 −2.896 19 GLU CD −3.194 7.442 −1.992 19 GLU OE1 −2.326 6.599 −1.686 19 GLU OE2 −4.375 7.339 −1.613 19 GLU HB1 −3.720 7.818 −4.667 19 GLU HB2 −2.044 7.314 −4.436 19 GLU HG1 −1.845 8.993 −2.521 19 GLU HG2 −3.546 9.409 −2.747 20 MET N 0.304 9.081 −5.411 20 MET CA 1.613 9.205 −4.724 20 MET HN 0.064 8.269 −5.989 20 MET HA 1.499 9.758 −3.773 20 MET C 2.703 9.961 −5.580 20 MET O 3.391 9.307 −6.372 20 MET CB 2.021 7.758 −4.320 20 MET HB1 1.924 7.072 −5.187 20 MET HB2 3.096 7.734 −4.080 20 MET CG 1.245 7.190 −3.111 20 MET SD 1.761 5.508 −2.777 20 MET CE 0.862 5.232 −1.245 20 MET HG1 1.366 7.818 −2.209 20 MET HG2 0.155 7.174 −3.311 20 MET HE1 0.982 4.201 −0.876 20 MET HE2 1.153 5.949 −0.457 20 MET HE3 −0.219 5.377 −1.430 21 PRO N 2.965 11.301 −5.432 21 PRO CA 4.032 12.006 −6.211 21 PRO CD 2.094 12.217 −4.662 21 PRO HA 3.958 11.712 −7.278 21 PRO HD1 1.931 11.903 −3.614 21 PRO HD2 1.100 12.301 −5.145 21 PRO C 5.513 11.694 −5.772 21 PRO O 5.777 10.728 −5.055 21 PRO CB 3.558 13.475 −6.078 21 PRO HB1 4.365 14.226 −6.161 21 PRO HB2 2.843 13.707 −6.894 21 PRO CG 2.833 13.550 −4.735 21 PRO HG1 2.144 14.412 −4.664 21 PRO HG2 3.555 13.637 −3.900 22 GLN N 6.492 12.482 −6.259 22 GLN CA 7.971 12.242 −6.117 22 GLN HN 6.130 13.269 −6.807 22 GLN HA 8.237 11.652 −7.014 22 GLN C 8.571 11.380 −4.938 22 GLN O 9.183 10.336 −5.185 22 GLN CB 8.687 13.611 −6.328 22 GLN HB1 9.776 13.432 −6.440 22 GLN HB2 8.393 14.021 −7.315 22 GLN CG 8.480 14.719 −5.249 22 GLN HG1 7.400 14.880 −5.075 22 GLN HG2 8.893 14.382 −4.280 22 GLN CD 9.089 16.086 −5.575 22 GLN OE1 9.447 16.412 −6.700 22 GLN NE2 9.203 16.949 −4.600 22 GLN HE21 8.880 16.664 −3.672 22 GLN HE22 9.586 17.853 −4.892 23 GLN N 8.363 11.795 −3.682 23 GLN CA 8.769 11.029 −2.462 23 GLN HN 7.850 12.681 −3.626 23 GLN HA 9.766 10.583 −2.655 23 GLN C 7.858 9.817 −2.049 23 GLN O 8.366 8.773 −1.628 23 GLN CB 8.984 12.075 −1.331 23 GLN HB1 9.753 12.795 −1.680 23 GLN HB2 9.473 11.581 −0.469 23 GLN CG 7.730 12.848 −0.815 23 GLN HG1 6.971 12.936 −1.613 23 GLN HG2 7.219 12.273 −0.019 23 GLN CD 8.018 14.281 −0.367 23 GLN OE1 8.162 15.184 −1.181 23 GLN NE2 8.113 14.540 0.911 23 GLN HE21 7.995 13.761 1.562 23 GLN HE22 8.301 15.524 1.123 24 ALA N 6.527 9.922 −2.191 24 ALA CA 5.598 8.770 −2.032 24 ALA HN 6.246 10.756 −2.719 24 ALA HA 5.810 8.295 −1.054 24 ALA C 5.702 7.618 −3.104 24 ALA O 5.540 6.445 −2.745 24 ALA CB 4.202 9.401 −1.926 24 ALA HB1 4.133 10.148 −1.112 24 ALA HB2 3.901 9.909 −2.861 24 ALA HB3 3.433 8.639 −1.708 25 ARG N 6.020 7.917 −4.378 25 ARG CA 6.491 6.901 −5.368 25 ARG HN 5.937 8.921 −4.609 25 ARG HA 5.870 6.003 −5.211 25 ARG C 7.958 6.348 −5.212 25 ARG O 8.226 5.246 −5.698 25 ARG CB 6.139 7.358 −6.810 25 ARG CG 6.910 8.577 −7.389 25 ARG CD 7.630 8.344 −8.738 25 ARG NE 8.675 7.276 −8.682 25 ARG CZ 9.882 7.391 −8.144 25 ARG NH1 10.343 8.483 −7.617 25 ARG NH2 10.647 6.350 −8.127 25 ARG HB1 5.050 7.561 −6.864 25 ARG HB2 6.250 6.485 −7.481 25 ARG HG1 6.185 9.408 −7.513 25 ARG HG2 7.623 8.968 −6.640 25 ARG HD1 6.870 8.070 −9.502 25 ARG HD2 8.049 9.297 −9.123 25 ARG HE 8.487 6.333 −9.036 25 ARG HH12 9.678 9.253 −7.562 25 ARG HH11 11.269 8.411 −7.176 25 ARG HH21 10.262 5.474 −8.478 25 ARG HH22 11.531 6.451 −7.608 26 GLN N 8.883 7.013 −4.478 26 GLN CA 10.024 6.300 −3.813 26 GLN HN 8.547 7.923 −4.141 26 GLN HA 10.567 5.729 −4.593 26 GLN C 9.557 5.221 −2.773 26 GLN O 9.940 4.063 −2.908 26 GLN CB 11.056 7.278 −3.178 26 GLN HB1 10.541 7.954 −2.472 26 GLN HB2 11.746 6.698 −2.531 26 GLN CG 11.938 8.128 −4.132 26 GLN HG1 12.574 8.807 −3.533 26 GLN HG2 11.290 8.808 −4.715 26 GLN CD 12.851 7.379 −5.112 26 GLN OE1 12.666 7.434 −6.322 26 GLN NE2 13.859 6.683 −4.658 26 GLN HE21 13.951 6.566 −3.644 26 GLN HE22 14.393 6.190 −5.379 27 LYS N 8.661 5.530 −1.814 27 LYS CA 7.965 4.488 −0.985 27 LYS HN 8.437 6.532 −1.767 27 LYS HA 8.749 3.968 −0.397 27 LYS C 7.205 3.320 −1.738 27 LYS O 6.925 2.294 −1.118 27 LYS CB 7.084 5.278 0.032 27 LYS CG 6.375 4.464 1.151 27 LYS CD 4.824 4.447 1.123 27 LYS CE 4.146 3.508 0.100 27 LYS NZ 4.039 4.152 −1.240 27 LYS HB1 6.354 5.914 −0.500 27 LYS HB2 7.736 6.020 0.539 27 LYS HG1 6.775 3.431 1.209 27 LYS HG2 6.683 4.897 2.125 27 LYS HD1 4.499 4.110 2.129 27 LYS HD2 4.421 5.479 1.064 27 LYS HE1 4.692 2.536 0.045 27 LYS HE2 3.132 3.226 0.470 27 LYS HZ1 3.433 4.985 −1.252 27 LYS HZ2 4.943 4.472 −1.617 27 LYS HZ3 3.653 3.537 −1.972 28 LEU N 6.852 3.447 −3.034 28 LEU CA 6.417 2.288 −3.875 28 LEU HN 7.273 4.279 −3.462 28 LEU HA 5.700 1.669 −3.298 28 LEU C 7.599 1.309 −4.230 28 LEU O 7.644 0.200 −3.695 28 LEU CB 5.656 2.809 −5.135 28 LEU HB1 6.358 3.414 −5.737 28 LEU HB2 5.429 1.941 −5.788 28 LEU CG 4.345 3.618 −4.944 28 LEU HG 4.521 4.455 −4.242 28 LEU CD1 3.889 4.207 −6.289 28 LEU HD11 3.626 3.417 −7.017 28 LEU HD12 2.996 4.851 −6.178 28 LEU HD13 4.664 4.825 −6.770 28 LEU CD2 3.199 2.752 −4.415 28 LEU HD21 2.261 3.324 −4.268 28 LEU HD22 2.945 1.949 −5.132 28 LEU HD23 3.435 2.251 −3.461 29 GLN N 8.551 1.701 −5.102 29 GLN CA 9.681 0.813 −5.525 29 GLN HN 8.445 2.659 −5.444 29 GLN HA 9.296 −0.228 −5.547 29 GLN C 10.927 0.704 −4.581 29 GLN O 11.555 −0.350 −4.563 29 GLN CB 10.058 1.100 −7.008 29 GLN HB1 10.824 0.361 −7.320 29 GLN HB2 9.184 0.826 −7.631 29 GLN CG 10.521 2.525 −7.440 29 GLN HG1 9.707 3.243 −7.230 29 GLN HG2 10.628 2.539 −8.541 29 GLN CD 11.813 3.109 −6.855 29 GLN OE1 11.817 4.184 −6.267 29 GLN NE2 12.940 2.471 −7.031 29 GLN HE21 12.865 1.517 −7.397 29 GLN HE22 13.731 2.870 −6.518 30 ASN N 11.300 1.729 −3.796 30 ASN CA 12.455 1.663 −2.841 30 ASN HN 10.673 2.543 −3.835 30 ASN HA 13.328 1.287 −3.409 30 ASN C 12.294 0.683 −1.616 30 ASN O 13.296 0.164 −1.122 30 ASN CB 12.777 3.128 −2.412 30 ASN HB1 12.124 3.435 −1.575 30 ASN HB2 12.518 3.827 −3.229 30 ASN CG 14.217 3.499 −2.051 30 ASN OD1 14.740 4.505 −2.512 30 ASN ND2 14.897 2.774 −1.201 30 ASN HD21 14.495 1.861 −0.955 30 ASN HD22 15.872 3.070 −1.104 31 LEU N 11.065 0.414 −1.141 31 LEU CA 10.771 −0.779 −0.283 31 LEU HN 10.324 0.878 −1.678 31 LEU HA 11.547 −0.852 0.505 31 LEU C 10.791 −2.187 −0.999 31 LEU O 11.021 −3.200 −0.334 31 LEU CB 9.400 −0.555 0.422 31 LEU HB1 8.613 −0.511 −0.357 31 LEU HB2 9.161 −1.468 1.000 31 LEU CG 9.234 0.657 1.379 31 LEU HG 9.418 1.589 0.808 31 LEU CD1 7.793 0.696 1.913 31 LEU HD11 7.540 −0.215 2.491 31 LEU HD12 7.624 1.560 2.582 31 LEU HD13 7.056 0.771 1.091 31 LEU CD2 10.205 0.614 2.572 31 LEU HD21 10.050 1.463 3.263 31 LEU HD22 10.099 −0.315 3.165 31 LEU HD23 11.260 0.669 2.244 32 PHE N 10.538 −2.258 −2.316 32 PHE CA 10.696 −3.495 −3.136 32 PHE HN 10.482 −1.340 −2.768 32 PHE HA 10.395 −4.364 −2.515 32 PHE C 12.179 −3.811 −3.566 32 PHE O 12.658 −4.914 −3.301 32 PHE CB 9.693 −3.392 −4.333 32 PHE HB1 9.145 −2.429 −4.348 32 PHE HB2 10.258 −3.342 −5.286 32 PHE CG 8.648 −4.516 −4.425 32 PHE CD1 8.796 −5.536 −5.370 32 PHE HD1 9.665 −5.563 −6.012 32 PHE CD2 7.508 −4.495 −3.613 32 PHE HD2 7.370 −3.707 −2.887 32 PHE CE1 7.815 −6.513 −5.511 32 PHE HE1 7.935 −7.287 −6.256 32 PHE CE2 6.530 −5.480 −3.751 32 PHE HE2 5.644 −5.463 −3.137 32 PHE CZ 6.679 −6.481 −4.707 32 PHE HZ 5.903 −7.220 −4.840 33 ILE N 12.931 −2.860 −4.163 33 ILE CA 14.249 −3.145 −4.844 33 ILE HN 12.381 −2.034 −4.432 33 ILE HA 14.130 −4.126 −5.346 33 ILE C 15.529 −3.369 −3.934 33 ILE O 16.676 −3.233 −4.369 33 ILE CB 14.418 −2.106 −6.019 33 ILE HB 13.426 −2.035 −6.516 33 ILE CG1 15.384 −2.601 −7.135 33 ILE HG11 15.188 −3.677 −7.326 33 ILE HG12 16.434 −2.566 −6.789 33 ILE CG2 14.822 −0.685 −5.541 33 ILE HG21 14.801 0.051 −6.363 33 ILE HG22 14.142 −0.317 −4.756 33 ILE HG23 15.844 −0.676 −5.117 33 ILE CD1 15.254 −1.881 −8.489 33 ILE HD11 14.229 −1.989 −8.896 33 ILE HD12 15.491 −0.806 −8.425 33 ILE HD13 15.936 −2.326 −9.236 34 ASN N 15.344 −3.823 −2.688 34 ASN CA 16.279 −4.802 −2.047 34 ASN HN 14.332 −3.912 −2.532 34 ASN HA 17.316 −4.527 −2.325 34 ASN C 16.140 −6.303 −2.523 34 ASN O 17.115 −7.053 −2.449 34 ASN CB 16.199 −4.624 −0.503 34 ASN HB1 16.971 −5.266 −0.040 34 ASN HB2 16.514 −3.598 −0.235 34 ASN CG 14.875 −4.948 0.199 34 ASN OD1 14.645 −6.042 0.695 34 ASN ND2 13.967 −4.009 0.275 34 ASN HD21 14.152 −3.184 −0.301 34 ASN HD22 13.053 −4.355 0.578 35 PHE N 14.955 −6.729 −2.996 35 PHE CA 14.720 −8.055 −3.644 35 PHE HN 14.230 −6.001 −3.022 35 PHE HA 15.681 −8.604 −3.688 35 PHE C 14.267 −7.997 −5.150 35 PHE O 14.703 −8.857 −5.922 35 PHE CB 13.790 −8.914 −2.732 35 PHE HB1 14.297 −9.051 −1.757 35 PHE HB2 13.757 −9.938 −3.149 35 PHE CG 12.346 −8.419 −2.481 35 PHE CD1 11.297 −8.823 −3.315 35 PHE HD1 11.490 −9.483 −4.149 35 PHE CD2 12.085 −7.518 −1.443 35 PHE HD2 12.890 −7.171 −0.812 35 PHE CE1 10.013 −8.316 −3.124 35 PHE HE1 9.216 −8.591 −3.799 35 PHE CE2 10.805 −7.002 −1.262 35 PHE HE2 10.636 −6.252 −0.503 35 PHE CZ 9.770 −7.402 −2.104 35 PHE HZ 8.787 −6.965 −2.001 36 CYS N 13.391 −7.059 −5.568 36 CYS CA 12.937 −6.919 −6.979 36 CYS C 12.642 −5.431 −7.337 36 CYS O 13.077 −4.984 −8.423 36 CYS CB 11.711 −7.838 −7.186 36 CYS SG 11.181 −7.821 −8.935 36 CYS OXT 11.882 −4.739 −6.619 36 CYS HN 13.082 −6.376 −4.869 36 CYS HA 13.741 −7.243 −7.669 36 CYS HB1 11.954 −8.878 −6.906 36 CYS HB2 10.872 −7.519 −6.542 36 CYS HG 10.855 −6.530 −9.009 END 1 CYS N 8.859 −12.826 −0.866 1 CYS CA 7.463 −12.830 −1.374 1 CYS HN1 9.334 −13.726 −0.991 1 CYS HN2 9.421 −12.087 −1.305 1 CYS HN3 8.864 −12.628 0.142 1 CYS HA 7.468 −13.235 −2.407 1 CYS C 6.828 −11.396 −1.494 1 CYS O 7.522 −10.392 −1.317 1 CYS CB 6.712 −13.837 −0.472 1 CYS SG 6.308 −13.188 1.176 1 CYS HB1 5.744 −14.101 −0.939 1 CYS HB2 7.235 −14.807 −0.360 2 TYR N 5.529 −11.294 −1.812 2 TYR CA 4.750 −10.029 −1.672 2 TYR HN 5.009 −12.171 −1.934 2 TYR HA 5.241 −9.395 −0.905 2 TYR C 3.318 −10.348 −1.118 2 TYR O 2.710 −11.362 −1.482 2 TYR CB 4.792 −9.194 −2.987 2 TYR HB1 4.452 −8.169 −2.757 2 TYR HB2 5.851 −9.037 −3.272 2 TYR CG 3.999 −9.693 −4.206 2 TYR CD1 4.589 −10.559 −5.132 2 TYR HD1 5.609 −10.885 −5.003 2 TYR CD2 2.682 −9.266 −4.405 2 TYR HD2 2.215 −8.590 −3.702 2 TYR CE1 3.859 −11.011 −6.232 2 TYR HE1 4.307 −11.690 −6.943 2 TYR CE2 1.957 −9.716 −5.506 2 TYR HE2 0.936 −9.388 −5.641 2 TYR CZ 2.547 −10.590 −6.416 2 TYR OH 1.833 −11.038 −7.494 2 TYR HH 0.967 −10.629 −7.471 3 TRP N 2.784 −9.498 −0.230 3 TRP CA 1.456 −9.732 0.411 3 TRP HN 3.400 −8.720 0.047 3 TRP HA 1.393 −10.807 0.685 3 TRP C 0.227 −9.448 −0.539 3 TRP O 0.394 −9.065 −1.703 3 TRP CB 1.498 −8.898 1.727 3 TRP HB1 2.506 −8.943 2.193 3 TRP HB2 1.353 −7.829 1.491 3 TRP CG 0.519 −9.345 2.820 3 TRP CD1 −0.639 −8.655 3.245 3 TRP CD2 0.588 −10.478 3.609 3 TRP NE1 −1.306 −9.343 4.282 3 TRP CE2 −0.520 −10.467 4.493 3 TRP HD1 −0.967 −7.716 2.824 3 TRP HE1 −2.095 −9.033 4.857 3 TRP CE3 1.538 −11.532 3.661 3 TRP HE3 2.409 −11.541 3.020 3 TRP CZ2 −0.682 −11.505 5.441 3 TRP HZ2 −1.510 −11.494 6.133 3 TRP CZ3 1.353 −12.549 4.598 3 TRP HZ3 2.088 −13.342 4.654 3 TRP CH2 0.260 −12.537 5.476 3 TRP HH2 0.160 −13.332 6.200 4 GLU N −1.026 −9.624 −0.065 4 GLU CA −2.251 −9.398 −0.900 4 GLU HN −1.066 −9.985 0.896 4 GLU HA −2.059 −9.850 −1.895 4 GLU C −2.579 −7.874 −1.150 4 GLU O −3.531 −7.282 −0.629 4 GLU CB −3.423 −10.225 −0.289 4 GLU CG −4.548 −10.658 −1.279 4 GLU CD −5.428 −9.594 −1.902 4 GLU OE1 −5.983 −8.751 −1.176 4 GLU OE2 −5.630 −9.609 −3.130 4 GLU HB1 −3.026 −11.161 0.155 4 GLU HB2 −3.858 −9.678 0.569 4 GLU HG1 −4.114 −11.254 −2.103 4 GLU HG2 −5.235 −11.354 −0.770 5 LEU N −1.753 −7.242 −1.991 5 LEU CA −1.972 −5.882 −2.541 5 LEU HN −0.922 −7.815 −2.212 5 LEU HA −3.057 −5.734 −2.704 5 LEU C −1.333 −5.919 −3.973 5 LEU O −1.967 −6.436 −4.899 5 LEU CB −1.517 −4.805 −1.497 5 LEU HB1 −0.421 −4.840 −1.373 5 LEU HB2 −1.897 −5.131 −0.508 5 LEU CG −2.002 −3.346 −1.723 5 LEU HG −3.062 −3.370 −2.045 5 LEU CD1 −1.930 −2.530 −0.421 5 LEU HD11 −2.500 −2.998 0.402 5 LEU HD12 −0.889 −2.404 −0.065 5 LEU HD13 −2.344 −1.512 −0.553 5 LEU CD2 −1.183 −2.584 −2.778 5 LEU HD21 −1.272 −3.021 −3.788 5 LEU HD22 −1.512 −1.532 −2.878 5 LEU HD23 −0.102 −2.555 −2.533 6 GLU N −0.102 −5.418 −4.147 6 GLU CA 0.670 −5.433 −5.427 6 GLU HN 0.318 −5.068 −3.279 6 GLU HA 0.760 −6.480 −5.776 6 GLU C 2.125 −4.958 −5.064 6 GLU O 3.021 −5.761 −4.797 6 GLU CB −0.062 −4.615 −6.547 6 GLU CG 0.643 −4.580 −7.927 6 GLU CD −0.149 −3.863 −8.997 6 GLU OE1 −0.877 −4.532 −9.753 6 GLU OE2 −0.072 −2.625 −9.100 6 GLU HB1 −1.073 −5.034 −6.699 6 GLU HB2 −0.241 −3.577 −6.203 6 GLU HG1 1.630 −4.089 −7.869 6 GLU HG2 0.842 −5.603 −8.299 8 TRP N 2.313 −3.638 −4.926 8 TRP CA 3.537 −2.986 −4.364 8 TRP HN 1.515 −3.090 −5.263 8 TRP HA 4.424 −3.433 −4.856 8 TRP C 3.848 −3.117 −2.821 8 TRP O 4.653 −2.346 −2.288 8 TRP CB 3.456 −1.496 −4.839 8 TRP HB1 4.309 −0.929 −4.424 8 TRP HB2 3.659 −1.485 −5.927 8 TRP CG 2.153 −0.690 −4.582 8 TRP CD1 1.178 −0.428 −5.575 8 TRP CD2 1.662 −0.105 −3.421 8 TRP NE1 0.101 0.325 −5.068 8 TRP CE2 0.430 0.525 −3.742 8 TRP HD1 1.240 −0.780 −6.598 8 TRP HE1 −0.765 0.609 −5.546 8 TRP CE3 2.173 −0.038 −2.098 8 TRP HE3 3.108 −0.507 −1.834 8 TRP CZ2 −0.283 1.234 −2.751 8 TRP HZ2 −1.204 1.736 −2.998 8 TRP CZ3 1.437 0.648 −1.130 8 TRP HZ3 1.792 0.681 −0.112 8 TRP CH2 0.230 1.282 −1.455 8 TRP HH2 −0.324 1.816 −0.694 8 LEU N 3.264 −4.088 −2.102 8 LEU CA 3.536 −4.329 −0.654 8 LEU HN 2.865 −4.819 −2.705 8 LEU HA 3.941 −3.411 −0.189 8 LEU C 4.558 −5.516 −0.479 8 LEU O 4.209 −6.629 −0.884 8 LEU CB 2.165 −4.593 0.042 8 LEU HB1 1.408 −3.926 −0.417 8 LEU HB2 1.824 −5.619 −0.207 8 LEU CG 2.061 −4.358 1.574 8 LEU HG 2.296 −3.294 1.781 8 LEU CD1 3.002 −5.228 2.425 8 LEU HD11 4.062 −4.953 2.285 8 LEU HD12 2.805 −5.135 3.510 8 LEU HD13 2.927 −6.303 2.177 8 LEU CD2 0.619 −4.623 2.040 8 LEU HD21 0.492 −4.415 3.118 8 LEU HD22 −0.111 −3.989 1.507 8 LEU HD23 0.316 −5.674 1.876 9 PRO N 5.780 −5.358 0.119 9 PRO CA 6.694 −6.502 0.430 9 PRO CD 6.411 −4.035 0.314 9 PRO HA 7.030 −6.917 −0.541 9 PRO HD1 6.017 −3.549 1.227 9 PRO HD2 6.254 −3.346 −0.539 9 PRO C 6.165 −7.738 1.254 9 PRO O 4.962 −7.953 1.399 9 PRO CB 7.873 −5.753 1.096 9 PRO HB1 8.834 −6.283 0.969 9 PRO HB2 7.706 −5.659 2.189 9 PRO CG 7.892 −4.373 0.455 9 PRO HG1 8.381 −4.416 −0.539 9 PRO HG2 8.450 −3.636 1.059 10 CYS N 7.083 −8.610 1.703 10 CYS CA 6.766 −10.017 2.059 10 CYS HN 8.045 −8.317 1.519 10 CYS HA 6.123 −10.428 1.255 10 CYS C 5.908 −10.281 3.352 10 CYS O 4.684 −10.146 3.295 10 CYS CB 8.136 −10.743 1.930 10 CYS SG 7.929 −12.525 2.158 10 CYS HB1 8.849 −10.378 2.694 10 CYS HB2 8.613 −10.553 0.953 11 ALA N 6.523 −10.747 4.456 11 ALA CA 5.941 −11.825 5.306 11 ALA HN 7.531 −10.788 4.308 11 ALA HA 6.701 −12.037 6.082 11 ALA C 5.832 −13.184 4.541 11 ALA O 6.858 −13.901 4.464 11 ALA OXT 4.767 −13.516 3.972 11 ALA CB 4.694 −11.381 6.092 11 ALA HB1 3.843 −11.199 5.412 11 ALA HB2 4.376 −12.169 6.797 11 ALA HB3 4.873 −10.456 6.664 END

TABLE V Residue NH C_(α)H C_(β)H C_(γ)H C_(δ)H Others Met1 4.159 2.124 2.566 2.012 Glu2 8.803 4.572 1.967 2.510, 2.319 Lys3 8.787 4.147 1.900 1.559, 1.431 1.729 2.969 Val4 8.314 3.889 2.132 1.026, 0.951 Gln5 7.846 4.092 2.364, 2.252 2.369 7.431, 6.823 Tyr6 7.924 4.225 3.114 7.046 6.780 Leu7 8.536 4.013 1.831 1.586 0.915 Thr8 7.975 3.955 4.247 1.222 Arg9 8.156 3.518 1.845, 1.725 1.587 3.092 7.242 Ser10 7.991 4.082 3.936, 3.767 Ala11 8.051 4.085 1.510 Ile12 8.126 3.681 1.857 1.704, 1.014 0.769 0.860 Arg13 8.181 3.983 1.941, 1.735 1.606 3.162 7.189 Arg14 8.143 4.052 1.941, 1.733 1.725, 1.604 3.169 7.154 Ala15 8.422 4.114 1.500 Ser16 8.110 4.275 4.029, 3.979 Thr17 7.695 4.316 4.373 1.270 Ile18 7.589 4.102 1.925 1.576, 1.216 0.851 0.912 Glu19 8.149 4.351 2.121, 2.011 2.468, 2.426 Met20 7.958 4.702 2.088 2.544 2.027 Pro21 4.487 2.539, 2.483 2.082, 1.948 3.876, 3.591 Gln22 8.766 4.008 2.173 2.438 7.433, 6.742 Gln23 8.954 4.079 2.084, 1945 2.464 7.457, 6.784 Ala24 7.455 4.155 1.474 Arg25 7.858 3.944 1.876, 1712 1.604 3.246, 3.181 7.253 Gln26 8.143 4.019 2.136, 2.115 2.461, 2.374 7.371, 6.721 Lys27 7.647 4.069 1.954, 1.598 1.613, 1.465 1.682 2.937, 7.604 Leu28 8.099 4.063 1.773, 1.712 1.510 0.849, 0.818 Gln29 8.212 3.985 2.198, 2.117 2.480, 2.367 7.172, 6.668 Asn30 7.908 4.482 2.884, 2.803 7.486, 6.821 Leu31 7.878 4.154 1.718, 1.625 1.557 0.859, 0.797 Phe32 8.162 4.430 3.238, 3.096 7.173 7.197 Ile33 7.974 3.986 1.930 1.611, 1.283 0.900 0.891 Asn34 7.801 4.570 2.588, 2.511 7.337, 6.759 Phe35 8.006 4.694 3.272, 3.058 7.277 7.207 Cys36 7.727 4.452 2.890

TABLE VI NMR assignments of cP226 in water. 1H-chemical shifts of cP226 in 90% H₂O/10% D₂O, pH 6.50 at 10° C.. Values expressed in ppm. res. HN HA HB1* HB2 HG* HD1/HD* HD2/HE* HE3 HZ2 Cys 1 4.054 2.991 2.896 Tyr 2 6.924 4.695 2.884 6.986 6.792 Trp 3 8.094 4.599 3.199 3.087 7.106 10.024 7.427 7.465 Glu 4 8.313 3.907 1.909 1.785 Leu 5 7.857 4.093 1.495 1.496 1.132 0.822 Glu 6 8.227 4.123 2.032 1.982 2.195 7.074 Trp 7 7.871 4.398 3.207 0.790 10.188 7.449 7.458 Leu 8 7.326 4.514 1.377 1.256 Pro 9 4.179 2.214 1.820 1.974 3.617 3.505 Cys 10 8.457 4.505 3.128 2.906 Ala 11 8.062 4.115 1.330

TABLE VII Quality of the structure of cP226 obtained by noe data RMSD values were calculated from a family od 12 structures without NOE restrain violation bigger than 0.3 Å. The local RMSD was calculated on 3 residues Global displacem. local RMSD Local displacem. NOEs res. bb heavy heavysc bb bb heavy heavysc (total) Cys 1 1.80 1.99 1.77 0.00 0.00 0.00 0.00 2 Tyr 2 0.92 3.52 4.23 0.72 0.59 3.21 3.86 6 Trp 3 0.76 1.36 1.50 0.35 0.26 0.73 0.81 17 Glu 4 0.83 2.22 2.86 0.29 0.23 1.77 2.33 12 Leu 5 0.63 1.38 1.78 0.26 0.20 1.04 1.44 23 Glu 6 0.73 2.34 3.00 0.26 0.24 1.73 2.23 9 Trp 7 0.65 2.06 2.39 0.27 0.25 1.67 1.96 16 Leu 8 0.53 1.55 2.11 0.18 0.16 1.58 2.22 27 Pro 9 0.60 0.83 1.04 0.17 0.12 0.18 0.21 15 Cys 10 0.71 0.94 1.11 0.27 0.18 0.36 0.54 13 Ala 11 1.20 1.67 1.73 0.00 0.00 0.00 0.00 6

Abbreviations

PLB, phospholamban; PLB[a.a.1-36], 36 a.a. N-terminal fragment of human phospholamban; SR, sarcoplasmic reticulum; SERCA, sarco/endoplasmic reticulum Ca²⁺-ATPase; SERCA_(—)2, cardiac isoform of the sarco/endoplasmic reticulum Ca²⁺-ATPase; CD, circular dichroism; COSY, correlation spectroscopy; TOCSY, total correlation spectroscopy; NOESY, nuclear Overhauser-enhancement spectroscopy; d₃-TFE, perdeuterated trifluoroethanol; d₁₀-DTT, perdeuterated dithiotreitol.

10 1 52 PRT Homo sapiens 1 Met Glu Lys Val Gln Tyr Leu Thr Arg Ser Ala Ile Arg Arg Ala Ser 1 5 10 15 Thr Ile Glu Met Pro Gln Gln Ala Arg Gln Lys Leu Gln Asn Leu Phe 20 25 30 Ile Asn Phe Cys Leu Ile Leu Ile Cys Leu Leu Leu Ile Cys Ile Ile 35 40 45 Val Met Leu Leu 50 2 52 PRT Sus sp. 2 Met Asp Lys Val Gln Tyr Leu Thr Arg Ser Ala Ile Arg Arg Ala Ser 1 5 10 15 Thr Ile Glu Met Pro Gln Gln Ala Arg Gln Lys Leu Gln Asn Leu Phe 20 25 30 Ile Asn Phe Cys Leu Ile Leu Ile Cys Leu Leu Leu Ile Cys Ile Ile 35 40 45 Val Met Leu Leu 50 3 52 PRT Canis sp. 3 Met Asp Lys Val Gln Tyr Leu Thr Arg Ser Ala Ile Arg Arg Ala Ser 1 5 10 15 Thr Ile Glu Met Pro Gln Gln Ala Arg Gln Asn Leu Gln Asn Leu Phe 20 25 30 Ile Asn Phe Cys Leu Ile Leu Ile Cys Leu Leu Leu Ile Cys Ile Ile 35 40 45 Val Met Leu Leu 50 4 52 PRT Oryctolagus cuniculus 4 Met Glu Lys Val Gln Tyr Leu Thr Arg Ser Ala Ile Arg Arg Ala Ser 1 5 10 15 Thr Ile Glu Met Pro Gln Gln Ala Arg Gln Asn Leu Gln Asn Leu Phe 20 25 30 Ile Asn Phe Cys Leu Ile Leu Ile Cys Leu Leu Leu Ile Cys Ile Ile 35 40 45 Val Met Leu Leu 50 5 52 PRT Rattus sp. 5 Met Glu Lys Val Gln Tyr Leu Thr Arg Ser Ala Ile Arg Arg Ala Ser 1 5 10 15 Thr Ile Glu Met Pro Gln Gln Ala Arg Gln Asn Leu Gln Asn Leu Phe 20 25 30 Ile Asn Phe Cys Leu Ile Leu Ile Cys Leu Leu Leu Ile Cys Ile Ile 35 40 45 Val Met Leu Leu 50 6 52 PRT Mus sp. 6 Met Glu Lys Val Gln Tyr Leu Thr Arg Ser Ala Ile Arg Arg Ala Ser 1 5 10 15 Thr Ile Glu Met Pro Gln Gln Ala Arg Gln Asn Leu Gln Asn Leu Phe 20 25 30 Ile Asn Phe Cys Leu Ile Leu Ile Cys Leu Leu Leu Ile Cys Ile Ile 35 40 45 Val Met Leu Leu 50 7 52 PRT Gallus sp. 7 Met Glu Lys Val Gln Tyr Ile Thr Arg Ser Ala Leu Arg Arg Ala Ser 1 5 10 15 Thr Leu Glu Val Asn Pro Gln Ala Arg Gln Arg Leu Gln Glu Leu Phe 20 25 30 Val Asn Phe Cys Leu Ile Leu Ile Cys Leu Leu Leu Ile Cys Ile Ile 35 40 45 Val Met Leu Leu 50 8 11 PRT Artificial Sequence Description of Artificial Sequence cyclic peptide pI 8 Cys Xaa Trp Glu Leu Glu Trp Leu Pro Cys Ala 1 5 10 9 36 PRT Artificial Sequence Description of Artificial Sequence cystolic part of phospholambam peptide 9 Met Glu Lys Val Gln Tyr Leu Thr Arg Ser Ala Ile Arg Arg Ala Ser 1 5 10 15 Thr Ile Glu Met Pro Gln Gln Ala Arg Gln Lys Leu Gln Asn Leu Phe 20 25 30 Ile Asn Phe Cys 35 10 11 PRT Artificial Sequence Description of Artificial Sequence linear or cyclic peptide cP226 10 Cys Tyr Trp Glu Leu Glu Trp Leu Pro Cys Ala 1 5 10 

We claim:
 1. A compound which is effective to deactivate a phospholamban having SEQ ID NO:1, SEQ ID NO:2, SEQ ID NO:3, SEQ ID NO:4, SEQ ID NO:5, SEQ ID NO:6, or SEQ ID NO:7 and which compound exhibits affinity for said phospholamban, wherein said compound comprises a structure that contains three of the following four moieties: (a) a first electronegative moiety associating with an S1 binding site of the phospholamban cytosolic domain when said compound is bound thereto, said S1 binding site comprising Tyr-6, Arg-9 and/or Arg-13, (b) a second electronegative moiety associating with an S2 binding site of the phospholamban cytosolic domain when said compound is bound thereto, said S2 binding site comprising Arg-14, (c) a first hydrophobic moiety associating with an S3 binding site of the phospholamban cytosolic domain when said compound is bound thereto, said S3 binding site comprising Met-20, Lys-27 and/or Leu-28, and (d) a second hydrophobic moiety associating with an S4 binding site of the phospholamban cytosolic domain when said compound is bound thereto, said S4 binding site comprising Phe-32 and/or Phe-35; provided that the compound is not 3-benzyl-5,7-bis((1H-tetrazol-5-yl)-methyloxy)-4-methyl-2H-1-benzopyran-2-one.
 2. A method of deactivating phospholamban which comprises administering to a mammal in need thereof a compound of claim 1 for a time and under conditions effective to stimulate CaATPase.
 3. A compound which is effective to deactivate a phospholamban having SEQ ID NO:1, SEQ ID NO:2, SEQ ID NO:3, SEQ ID NO:4, SEQ ID NO:5, SEQ ID NO:6, or SEQ ID NO:7 and which compound exhibits affinity for said phospholamban, wherein said compound comprises a structure that contains three of the following four moieties: (a) a first electronegative moiety associating with an S1 binding site of the phospholamban cytosolic domain when said compound is bound thereto, said S1 binding site comprising Tyr-6, Arg-9 and/or Arg-13, (b) a second electronegative moiety associating with an S2 binding site of the phospholamban cytosolic domain when said compound is bound thereto, said S2 binding site comprising Arg-14, (c) a first hydrophobic moiety associating with an S3 binding site of the phospholamban cytosolic domain when said compound is bound thereto, said S3 binding site comprising Met-20, Lys-27 and/or Leu-28, and (d) a second hydrophobic moiety associating with an S4 binding site of the phospholamban cytosolic domain when said compound is bound thereto, said S4 binding site comprising Phe-32 and/or Phe-35; provided that said compound is other than a compound of formula (I):

 where X and Y are O, R1 is aryl or aralkyl, R3 is hydrogen or alkyl, R2 is hydrogen or methyl, A is —CH₂— or —CH₂—CH₂—, and R4 and R5 are tetrazol-5-yl.
 4. A compound of claim 3 comprising any three of the following four moieties: (a) a first electronegative moiety forming a hydrogen bond with the —OH group of Tyr-6, a salt bridge with the guanidinium group of Arg-9 and/or a salt bridge with the guanidinium group of Arg-13, of the phospholamban cytosolic domain when said compound is bound thereto, (b) a second electronegative moiety forming a salt bridge with the guanidinium group of Arg-14 of the phospholamban cytosolic domain when said compound is bound thereto, (c) a first hydrophobic moiety associating with a hydrophobic pocket created by Met-20, Lys-27 and/or Leu-28, of the phospholamban cytosolic domain when said compound is bound thereto, and (d) a second hydrophobic moiety associating with a hydrophobic pocket created by Phe-32 and/or Phe-35 of the phospholamban cytosolic domain when said compound is bound thereto.
 5. A compound of claim 3 comprising: (a) a first electronegative moiety forming a hydrogen bond with the —OH group of Tyr-6, a salt bridge with the guanidinium group of Arg-9 and/or a salt bridge with the guanidinium group of Arg-13, of the phospholamban cytosolic domain when said compound is bound thereto, (b) a second electronegative moiety forming a salt bridge with the guanidinium group of Arg-14 of the phospholamban cytosolic domain when said compound is bound thereto, and (c) a first hydrophobic moiety associating with a hydrophobic pocket created by Met-20, Lys-27 and/or Leu-28, of the phospholamban cytosolic domain when said compound is bound thereto.
 6. A composition comprising a compound of claim 3 as the active ingredient in admixture with a pharmaceutically acceptable carrier. 